tag:blogger.com,1999:blog-19254534589058238772024-03-17T22:12:43.458-04:00Freshwater Gastropods of North AmericaRob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.comBlogger279125tag:blogger.com,1999:blog-1925453458905823877.post-70291499405875101502024-03-12T14:03:00.003-04:002024-03-17T22:12:10.140-04:00Lymnaea (Galba) cockerelli, Number 15.<p>Bengt Hubendick <b><span style="color: #783f04;">[1]</span></b> recognized 13 valid species of lymnaeid
snails in North America <b><span style="color: #783f04;">[2]</span></b>, setting aside the patelliform genus <i>Lanx</i>, which he
did not treat. To that tally should be
added <i>L. auricularia</i>, introduced to this continent more recently, and <i><a href="https://www.fwgna.org/species/lymnaeidae/l_caperata.html" target="_blank">L. caperata</a></i>, which Hubendick mistakenly synonymized under <a href="https://www.fwgna.org/species/lymnaeidae/l_humilis.html" target="_blank">L. <i>humilis</i></a>. Oh, and subtract <i>emarginata</i> from Hubendick’s
list, a junior synonym of <a href="https://www.fwgna.org/species/lymnaeidae/l_catascopium.html" target="_blank">L. <i>catascopium</i></a>.
Is that the complete continental fauna?
To Hubendick’s canonical list of 13 + 2 – 1 = 14 species of <i>Lymnaea</i> inhabiting
the waters of North America, might be added a Number 15?</p><p>Yes. Last month
[<a href="https://fwgna.blogspot.com/2024/02/what-is-lymnaea-bulimoides.html" target="_blank">13Feb24</a>] we reviewed the long and tortured history of Isaac Lea’s <b><span style="color: #783f04;">[3]</span></b> nomen
<i><a href="https://www.fwgna.org/species/lymnaeidae/l_bulimoides.html" target="_blank">Lymnaea bulimoides</a></i>, recognized as distinct by Hubendick but much confused by many other authorities with another of
Hubendick’s canonical species, <i><a href="https://www.fwgna.org/species/lymnaeidae/l_cubensis.html" target="_blank">Lymnaea cubensis</a></i>. We reproduced images of 23 shells in that
overly long essay. I have subtracted the
twelve images of <i>L. cubensis/viator </i>and other miscellaneous lymnaeids and
re-reproduced the remaining eleven images as thumbnails in a single montage
below, adding five images of related taxa I mentioned in passing last month but
didn’t figure.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7pKD5icPvPbpGA3tNegz7QCfJY_2hZXyO4cmItc2ljyQWBpPyzW67x54Dd1EMAKgFjbeYKj9hoKYorj6C9clBkSI-j6eodN-VqFPy6VGh8kkh5PK4Xi9tsb_l0Iw4-L7C5jK07I76Xlj6BOCBAK_Bwjzb3BDSg13lypTuF-cnWjP2bvKUdvxUKavhbZ8s/s306/bulimoides-cockerelli.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="306" data-original-width="210" height="306" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7pKD5icPvPbpGA3tNegz7QCfJY_2hZXyO4cmItc2ljyQWBpPyzW67x54Dd1EMAKgFjbeYKj9hoKYorj6C9clBkSI-j6eodN-VqFPy6VGh8kkh5PK4Xi9tsb_l0Iw4-L7C5jK07I76Xlj6BOCBAK_Bwjzb3BDSg13lypTuF-cnWjP2bvKUdvxUKavhbZ8s/s1600/bulimoides-cockerelli.jpg" width="210" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">See footnote <b><span style="color: #783f04;">[4]</span></b> for complete caption.</span></td></tr></tbody></table><p>Does that set of thumbnail figures look homogeneous to you? Or, just on the basis of those 16 shell images, knowing nothing about the biology of the snails that bore
them, could you divide the set above into two distinct subsets? Let’s back up 118 years and get a fresh start
at that question.</p><p>It will be remembered from last month’s essay that in 1906
Henry Pilsbry and James Ferriss <b><span style="color: #783f04;">[8]</span></b> recognized four subspecies of <i>Lymnaea
bulimoides</i>. The typical form, originally
described from the Oregon Territory in 1841, is depicted in thumbnails A, B, C,
K, and M. The (essentially
indistinguishable) <i>techella</i> form, described from Texas in 1867, is depicted in
thumbnails D, E, I, and O. To these
Pilsbry and Ferriss added a <i>sonomaensis</i> form (G, P) from California, and their
own brand new <i>cockerelli</i> (F, J, L, N), from New Mexico, Colorado, Nebraska and
South Dakota. Quoting Pilsbry verbatim:</p><p></p><blockquote><span style="font-size: x-small;">“This form (<i>cockerelli</i>) differs from <i>L. bulimoides</i> and <i>L.
techella</i> by its more globose shape and shorter spire, and so far as we have
seen is readily separable from both.”</span></blockquote><p></p><p>In 1909 Pilsbry’s disciple, Frank Collins Baker <b><span style="color: #783f04;">[13]</span></b>, raised
<i>sonomaensis</i> to the full species level and described a new <i>Lymnaea hendersoni</i>
from Colorado, “at first thought to be <i>sonomaensis</i>” but “differing in the form
of the spire and aperture.” And in 1911
Baker <b><span style="color: #783f04;">[14]</span></b> published his landmark monograph on the “Lymnaeidae of North
America, Recent and Fossil,” cataloging and reviewing 103 species and
subspecies in 15 genera, subgenera, and groups <b><span style="color: #783f04;">[15]</span></b>, including all five of the
lymnaeid taxa listed above in exhaustive detail.</p><p>The figure below is a concatenation of Baker’s <b><span style="color: #783f04;">[16]</span></b> plate
XXVII (figs 20 – 35) and plate XXVIII (figs 1 – 19). Figures 20 – 29 are <i>Galba bulimoides </i>(ss), figure 25 being the holotype, the same shell as figure as A above. Baker identified figures 1 – 3, 8, and 30 –
35 as <i>Galba bulimoides techella</i>, figures 4 -
7 as <i>G. bulimoides cockerelli</i>, figures 9 – 11 as a new form <i>G.
bulimoides cassi</i>, figs 12 – 14 as <i>G. sonomaensis</i>, figs 15 – 18 as his <i>G.
hendersoni</i>, and fig 19 as <i>Galba perpolita</i>, more about which anon.</p><p>To my eye, this montage of 35 shells is as naturally and
easily divisible into two sets as the montage of 16 thumbnails that opened this
essay. I distinguish a set that looks
like the <i>bulimoides</i> holotype (#25), which includes all those Baker identified
as <i>techella</i> and <i>cassi</i>, and a subset with a much larger, more inflated body
whorl, identified by Baker as <i>cockerelli, sonomaensis, hendersoni</i>, and
<i>perpolita</i>.</p><p>Focus with me now on figs 4 – 7, depicting <i>G. bulimoides
cockerelli</i> (three populations), and try to compare that subset of four shells
with all the other (N = 23) images of shells borne by all the other subspecies
of <i>bulimoides</i>: 1 – 3, 8 – 11, 20 – 35. I
know that’s a challenge, but humor me, OK?
Those two subsets clearly belong to different sets, can you see what I am
saying? Why in the world would splitters
as practiced in their art as Pilsbry and Baker identify the snails bearing all
27 of those shells as a single species?
Especially when they split out figs 12 – 14 as a separate species
<i>sonomaensis</i>? And figs 15 – 18 as a
separate species <i>hendersoni</i>?</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjR7yiVUnResuLgiKSUyN_6LRxTDXN7MqQlePbj_gFr-dmZeqqEY21n9OVlXLt1K4e4R3fC0ZTPbwpVzs9F1zLCLw9VN1OipdUoER1kzqGxcWTnUPdMMhO-a6GsarigBhYW2S-mBuFDa84emXoTbe8l-FqF8gc_MfymadWXdbmMMOvDBzX2gJ6vMBh5k5EA/s3821/Baker-bulimoides-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3821" data-original-width="2619" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjR7yiVUnResuLgiKSUyN_6LRxTDXN7MqQlePbj_gFr-dmZeqqEY21n9OVlXLt1K4e4R3fC0ZTPbwpVzs9F1zLCLw9VN1OipdUoER1kzqGxcWTnUPdMMhO-a6GsarigBhYW2S-mBuFDa84emXoTbe8l-FqF8gc_MfymadWXdbmMMOvDBzX2gJ6vMBh5k5EA/w274-h400/Baker-bulimoides-montage.jpg" width="274" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Baker <b><span style="color: #783f04;">[14]</span></b> plates 27, 28. See <b><span style="color: #783f04;">[16]</span></b> for scale.</span></td></tr></tbody></table><p>The answer lies in the subset of five shells boxed in
red. This is a sample collected from the
rural community of Bardsdale in Ventura County, CA, that weighed heavily in
Baker’s calculations. He wrote, in the
“Remarks” section of his treatment of <i>cockerelli</i>, that “Specimens from Ventura County, California,
show a tendency to vary toward the <i>techella</i> form of shell, clearly showing that
the <i>cockerelli </i>race is an offshoot of <i>techella</i>.” That sentence is phrased as though he wanted
to identify the entire Bardsdale population as <i>cockerelli</i>, but when the time
came to his assemble plates, Baker split five specimens from Bardsdale
three-and-two.</p><p>Well, shoot. I reckon
if there’s any splittin’ to be done around these parts, Sheriff Dwight Taylor
is the man for the job. In 1960 Taylor
teamed up with vertebrate paleontologist Claude W. Hibbard on a 223-page
monograph <b><span style="color: #783f04;">[17]</span></b> of “two late Pleistocene faunas from southwestern Kansas.” Hibbard & Taylor identified nine species
of lymnaeids in the prehistoric fauna of the Great Plains, including <i><a href="https://www.fwgna.org/species/lymnaeidae/l_stagnalis.html" target="_blank">Lymnaea stagnalis</a></i>, six nominal species of <i>Stagnicola</i>, and two nominal species of
<i>Fossaria</i>. And as they sorted out the
<i>Stagnicola</i> <b><span style="color: #783f04;">[18]</span></b>, Hibbard and Taylor observed, “from a review of previous
literature and on examination of specimens it appears that <i>Stagnicola
bulimoides cockerelli</i> is specifically distinct from <i>S. bulimoides</i> and <i>S.
bulimoides techella</i>.”</p><p>Taylor further observed that the geographic ranges of
<i>bulimoides</i> and <i>cockerelli</i> are different (although overlapping), <i>cockerelli</i>
being the only species to extend through the northern Great Plains, and that
the “apparent lack of intergradation” where <i>bulimoides</i> and <i>cockerelli</i> do
overlap (in the Southwest, for example) might be viewed with special
significance. Here the young Dwight W. Taylor
of 1960 seems almost to flirt with the biological species concept <b><span style="color: #783f04;">[19]</span></b>. Taylor went on to re-identify the red-box
population of <i>cockerelli </i>that Baker figured from Bardsdale as <i>bulimoides
techella</i> in its entirety, and to synonymize Baker’s (1911) <i>hendersoni</i> under
<i>cockerelli</i>.</p><p>And in 1973, Joe Bequaert
& Walter Miller brought Taylor’s point home <b><span style="color: #783f04;">[20]</span></b>. In their landmark “Mollusks of the Arid
Southwest with an Arizona Check list,” Bequaert & Miller relayed the
following report:</p><p></p><blockquote><span style="font-size: x-small;">“R. H. Russell informs us that he found in 1969 thriving
colonies of <i>S. b. techella</i> and <i>S. cockerelli</i> living together (sympatric) in the
same pond at two stations in Navajo Co. (O’Haco Farm and Sitting Bull Trading
Post), without transitional specimens or other evidence of interbreeding in
nature.”</span></blockquote><p></p><p>And indeed. Returning
a second time to F. C. Baker’s red-box sample from Bardsdale. I do not agree with Taylor that the snails
bearing all five of the shells boxed in red above are best identified as <i>L.
bulimoides techella</i>. To my eye, it
appears that Baker’s original identifications distinguished two distinct
biological species: Figs 6 and 7 <i>L. cockerelli</i> and Figs. 33 – 35 <i>L. bulimoides</i>. The Bardsdale collection appears to have been
made from a site where a pair of reproductively isolated species co-occur, just
as in Arizona.</p><p>In conclusion.
<b><i>Lymnaea cockerelli</i> Pilsbry and Ferriss 1906 is a distinct and valid biological
species</b>, reproductively isolated from <i>L. bulimoides</i> Lea 1841 and all 13 other North American
species of lymnaeids. Junior synonyms of
<i>L. cockerelli</i> include <i>sonomaensis</i> Hemphill 1906 and <i>hendersoni</i> Baker 1909. <i>Lymnaea perpolita</i> Dall 1905 may be a senior
synonym.</p><p>Yes, doggone it. Look
back with me at Figure 19 on the plate of shells I concatenated from Baker
<b><span style="color: #783f04;">[14]</span></b> above. That is an image that Baker
borrowed from William Healy Dall’s 1905 monograph on the land and freshwater
mollusks collected by the 1899 Harriman Expedition to Alaska <b><span style="color: #783f04;">[21]</span></b>. On his pages 78 – 79 Dall described a single
“small, translucent, dark amber color” shell collected at Nushagak, Bristol
Bay, Alaska as <i>Lymnaea (Stagnicola?) perpolita</i> n. sp. It really looks to me like Dall may have
scooped Pilsbry and Ferriss by one year.</p><p>But as far as I can tell, Dall’s nomen <i>perpolita</i> has almost
never <b><span style="color: #783f04;">[22] </span></b>been applied to any other population of snails ever collected again,
while Pilsbry and Ferriss’ <i>cockerelli</i> has seen wide use throughout western
North America. Forget that you read
these last two paragraphs. I never wrote
them.</p><p>So to summarize, over last month’s essay and this month’s
as well. Isaac Lea’s (1841) nomen
<i>Lymnaea bulimoides</i> has been applied to populations of at least three distinct
biological species, including <i>cubensis/viator</i> and <i>cockerelli</i> as well to as to
the bona fide <i>bulimoides</i> of “Oregon” as originally described. The eastern extent of the <i>L. bulimoides</i> range
has been overstated. My buddy Bruce
Stephen and I have not been able to confirm populations of bona fide <i>L.
bulimoides</i> anywhere in Kansas, Nebraska, or The Dakotas. Populations of both <i>L. cubensis/viator</i> and <i>L.
cockerelli</i> are not uncommon in those states, however.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRq2yVusE6D-sWzYtckzOvEZ0ymGlanCb9Xb6cpTZsZ6bfS32X1ypSASArJZX-5GOMlEacXQqy2kZRhkirQ0LA9Yr9lH9wP8g8mVPwpiRefIyLZml_WL0AC5720NtEdqeL9_fHKs7sbt9O035Z_FSQsjPxjSMr-TaDSlKglW5hSesU8cNlbronqn9gHR6_/s1734/cockerelli-table.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="820" data-original-width="1734" height="151" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRq2yVusE6D-sWzYtckzOvEZ0ymGlanCb9Xb6cpTZsZ6bfS32X1ypSASArJZX-5GOMlEacXQqy2kZRhkirQ0LA9Yr9lH9wP8g8mVPwpiRefIyLZml_WL0AC5720NtEdqeL9_fHKs7sbt9O035Z_FSQsjPxjSMr-TaDSlKglW5hSesU8cNlbronqn9gHR6_/w320-h151/cockerelli-table.jpg" width="320" /></a></div><p>Then opening the Burch Bible <b><span style="color: #783f04;">[12]</span></b> to pages 172 – 174 we find
five (full) species listed under <i>Fossaria (Bakerilymnaea)</i>, the subgenus set
aside for crappy little amphibious lymnaeids with bicuspid first laterals. Under the first of those species, <i>Fossaria
(Bakerilymnaea) bulimoides</i>, we find six subspecies. In the table above I have listed those 12
taxa together with our modern FWGNA understanding of their identities. For the time being. Additional data would be most welcome.</p><p><br /></p><p><u>Notes</u>:</p><p><b><span style="color: #783f04;">[1]</span></b> Hubendick, B. (1951)
Recent Lymnaeidae. Their
variation, morphology, taxonomy, nomenclature and distribution. Kungliga Svenska Vetenskapsakademiens
Handlingar Fjarde Serien 3: 1 - 223.</p><p><b><span style="color: #783f04;">[2]</span></b> Hubendick listed three species as Holarctic: <i>stagnalis,
truncatula</i>, and “<i>palustris</i>,” by which he was referring to populations better
identified as <i>elodes</i> here. As unique to
North America, he listed ten: <i>humilis, cubensis, bulimoides, catascopium,
emarginata, columella, megasoma, haldemani, arctica</i> and “<i>utahensis</i> (?)” I would add a second question mark behind
<i>utahensis</i>. In fact, I’m not 100% sold on
<i>haldemani</i>.</p><p><b><span style="color: #783f04;">[3]</span></b> Lea, Isaac (1841) On fresh water and land shells
(continued). Proceedings of the American
Philosophical Society 2(17): 30 – 34.</p><p><b><span style="color: #783f04;">[4]</span></b> Original identification and authority for the 16 shells
depicted, with standard length if it is known or can be estimated: (A) Lea’s <i>bulimoides</i> holotype 9.3 mm, (B)
<i>bulimoides</i> from Haldeman <b><span style="color: #783f04;">[5]</span></b>, (C) <i>bulimoides</i> from Binney<b><span style="color: #783f04;"> [6]</span></b>, (D) <i>techella</i> from
Haldeman <b><span style="color: #783f04;">[7]</span></b>, (E) <i>techella</i> from Pilsbry<b><span style="color: #783f04;"> [8]</span></b> 13.0 mm, (F) <i>cockerelli</i> from
Pilsbry <b><span style="color: #783f04;">[8]</span></b> 10.0 mm, (G) <i>sonomaensis</i> from Pilsbry <b><span style="color: #783f04;">[8]</span></b> 10.0 mm, (H)
<i>vancouverensis</i> from Baker <b><span style="color: #783f04;">[9]</span></b> 18.5 mm, (I) <i>techella</i> from Clarke <b><span style="color: #783f04;">[10]</span></b> 10.6 mm,
(J) <i>cockerelli</i> from Clarke <b><span style="color: #783f04;">[10]</span></b> 5.5 mm, (K) <i>bulimoides</i> from Clarke <b><span style="color: #783f04;">[10]</span></b> 12.0
mm, (L) <i>cockerelli</i> from Leonard <b><span style="color: #783f04;">[11],</span></b> (M) <i>bulimoides</i> from Burch <b><span style="color: #783f04;">[12]</span></b> 13.8 mm,
(N) <i>cockerelli</i> from Burch <b><span style="color: #783f04;">[12]</span></b> 13.8 mm, (O) <i>techella</i> from Burch <b><span style="color: #783f04;">[13]</span></b> 13.1 mm,
(P) <i>sonomaensis</i> from Burch <b><span style="color: #783f04;">[12]</span></b> 6.9 mm.</p><p><b><span style="color: #783f04;">[5]</span></b> Haldeman, S.S. (1844) A monograph of the freshwater
univalve Mollusca of the United States, Number 7 Philadelphia: Cary & Hart, Dobson, and
Pennington. 32 pp, 4 plates.</p><p><b><span style="color: #783f04;">[6]</span></b> Binney, W.G. (1865) Land and fresh water shells of North
America Part II, Pulmonata Limnophila and Thalassophila. Smithsonian
Miscellaneous Collections 143: 1 – 161.</p><p><b><span style="color: #783f04;">[7]</span></b> Haldeman, S.S. 1867
Description of a new species of <i>Limnaea</i>.
American Journal of Conchology 3: 194.</p><p><b><span style="color: #783f04;">[8]</span></b> Pilsbry, H.A. and J.H. Ferriss (1906) Mollusca of the southwestern states II. Proceedings of the Academy of Natural
Sciences of Philadelphia 58: 123 – 175.</p><p><b><span style="color: #783f04;">[9] </span></b>F. C. Baker’s brief (1939) description of <i>Stagnicola
bulimoides vancouverensis nov. var</i>. was published in The Nautilus 52(4):
144. The figure reproduced above
followed in Nautilus 53(1) plate 7.</p><p><b><span style="color: #783f04;">[10]</span></b> Clarke, A. (1973) The freshwater molluscs of the
Canadian Interior Basin. Malacologia, 13, 1-509.</p><p><b><span style="color: #783f04;">[11]</span></b> Leonard, A.B. (1959) Handbook of Gastropods in Kansas.
Miscellaneous Publications of the University of Kansas Museum of Natural
History 20: 1 – 224.</p><p><b><span style="color: #783f04;">[12] </span></b>This is a difficult work to cite. J. B. Burch's North American Freshwater
Snails was published in three different ways.
It was initially commissioned as an identification manual by the US EPA
and published by that agency in 1982. It
was also serially published in the journal Walkerana (1980, 1982, 1988) and
finally as stand-alone volume in 1989 (Malacological Publications, Hamburg, MI).</p><p><b><span style="color: #783f04;">[13]</span></b> Baker, F.C. (1909) A new species of <i>Lymnaea</i>. The Nautilus 22: 140 – 141.</p><p><b><span style="color: #783f04;">[14]</span></b> Baker, F.C. (1911) The Lymnaeidae of North and Middle
America, Recent and Fossil. Chicago
Academy of Sciences, Special Publication Number 3. 539 pp.</p><p><b><span style="color: #783f04;">[15]</span></b> Note that the number of genera, subgenera, and other higher-level "groups" recognized by Baker in the North American Lymnaeidae is exactly the number of valid biological species. This is not a coincidence.</p><p><b><span style="color: #783f04;">[16] </span></b>Quoting the caption to Plate XXVII, Figs 20 – 35 were
“enlarged about two diameters” at their reproduction, and on that basis I have
added the red scale bar. Figs 1 – 19
were mostly “enlarged 2 diameters” on their original plate XXVIII, with the
exceptions of figs 12 – 14 “enlarged about three diameters,” and fig 19, “1.5
diameters.”</p><p><b><span style="color: #783f04;">[17]</span></b> Hibbard, C.W. and D.W. Taylor (1960) Two late
Pleistocene faunas from southwestern Kansas.
Contributions from the Museum of Paleontology, University of Michigan
16(1): 1 – 223.</p><p><b><span style="color: #783f04;">[18]</span></b> Yes, Dwight
Taylor considered <i>L. bulimoides</i> to be a little <i>Stagnicola</i>, not a big
<i>Galba/Fossaria</i>. F.C. Baker made exactly
the same judgement call in 1939, see footnote #17 of last month’s essay. This is yet further support, if any is
needed, for Hubendick’s <b><span style="color: #783f04;">[1] </span></b>opinion that there is insufficient morphological
basis for the recognition of genera within the family Lymnaeidae. The FWGNA follows Hubendick in assigning all
North American lymnaeids (except the patelliform genus <i>Lanx</i>) to the typical genus <i>Lymnaea</i>, adding (subgenera) for
their indexing function alone. We do not
assign Lea’s <i>bulimoides</i> to <i>Lymnaea (Galba)</i> to transmit any hypothesis of
evolutionary relationship whatsoever, but only because “<i>Galba</i>” seems to connect with the
greatest fraction of the recent literature.</p><p><b><span style="color: #783f04;">[19]</span></b> I never met the reclusive millionaire Dwight Taylor,
but the dark shadow he cast over freshwater and terrestrial malacology extended
far beyond the American West. Well, even
a sundial facing west will be right once a day.</p><p><b><span style="color: #783f04;">[20]</span></b> Bequaert, J. & W. Miller (1973) The Mollusks of the Arid Southwest, with an Arizona Check List. Tucson: University of Arizona Press. </p><p><b><span style="color: #783f04;">[21]</span></b> Dall, W. H.
(1905) Land and fresh water mollusks of
Alaska and adjoining regions.
Smithsonian Institution Harriman Alaska Series 13: 1 – 171.</p><p><b><span style="color: #783f04;">[22]</span></b> My search of the iDigBio database <b><span style="color: #783f04;">[23]</span></b> for family =
Lymnaeidae and species = <i>perpolita</i> returned 12 hits in the USNM from Alaska and
two hits in the University of Alaska Museum from Iceland. Very little data on any of the 14 – not even
dates of collection for the USNM records.</p><p><b><span style="color: #783f04;">[23]</span></b> For more about iDigBio, see:</p><p></p><ul style="text-align: left;"><li>20 Years of Progress in the Museums [<a href="https://fwgna.blogspot.com/2019/05/20-years-of-progress-in-museums.html" target="_blank">22May19</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-85011141797217007372024-02-13T17:29:00.007-05:002024-03-03T13:53:34.152-05:00What is Lymnaea bulimoides?<p>Thomas Nuttall (1786 – 1859) was a pioneering naturalist on
the American frontier, most famous as a botanist but with interests in geology,
ornithology, and yes, malacology as well.
In 1834 he resigned his professorship at Harvard and joined an
expedition up the newly-opening <b><span style="color: #783f04;">[1]</span></b> Oregon Trail. Nuttall spent most of the next two years in
the Pacific Northwest, interrupted by an exursion to Hawaii, returning to a
position at the Academy of Natural Sciences of Philadelphia in 1836.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9-rrQ0sMAfN1muMslbifgj0U16rzEcyG30ZBQTp5-iniEcUy-8LtlFy7vRy00YEkBG5hnmMXhbjEVaybr4Zy4GdIXWXUcjZpYx0s3Q4yweZN4Iny4WCvxZOW4GCeQG4ZTf3YknIZ6R15sWPlcSBsizMeRZhhl89aulAzHR-ULsuU2y3PGy1nRV0MVR-y0/s2000/L-bulimoides-holotype-USNM.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1643" data-original-width="2000" height="164" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9-rrQ0sMAfN1muMslbifgj0U16rzEcyG30ZBQTp5-iniEcUy-8LtlFy7vRy00YEkBG5hnmMXhbjEVaybr4Zy4GdIXWXUcjZpYx0s3Q4yweZN4Iny4WCvxZOW4GCeQG4ZTf3YknIZ6R15sWPlcSBsizMeRZhhl89aulAzHR-ULsuU2y3PGy1nRV0MVR-y0/w200-h164/L-bulimoides-holotype-USNM.jpg" width="200" /></a></div><p>In 1841 our old buddy Isaac Lea <b><span style="color: #783f04;">[2]</span></b> published a brief,
Latinate description of <i><a href="https://www.fwgna.org/species/lymnaeidae/l_bulimoides.html" target="_blank">Lymnaea bulimoides</a> </i><b><span style="color: #783f04;">[3]</span></b>, which he followed with an
English translation in 1844, as follows <b><span style="color: #783f04;">[4]</span></b>:</p><p></p><blockquote><span style="font-size: x-small;">"Shell ovately conical, rather thin, smooth, shining,
diaphanous, brownish yellow, slightly perforate; spire rather short; sutures
small; whorls five, slightly convex; aperture ovate. Hab. Oregon, Prof.
Nuttall."</span></blockquote><p></p><p>Alas, Lea never published a figure of his <i>Lymnaea
bulimoides</i>. And the “Oregon” from which
Prof. Nuttall had just fetched that first sample was a vast territory that
included all of the modern states of Washington and Idaho, parts of Montana and
Wyoming and most of British Columbia <b><span style="color: #783f04;">[5]</span></b>.</p><p>By the blessings of Divine Providence, however, Lea’s type
lot has been preserved, even unto the present day. Both Haldeman <b><span style="color: #783f04;">[6]</span></b> and Binney <b><span style="color: #783f04;">[7] </span></b>published
little 1:1 figures of “authentic specimens,” as reproduced below. Prof. Haldeman <b><span style="color: #783f04;">[8] </span></b>added a very similar
looking <i>Limnea techella </i>from Texas to the literature in 1867 as “surface
smoother than in <i>L. bulimoides</i>, of Oregon, with the lines of accretion less
apparent, and the labium more angular.”
His little 1:1 figure of <i>L. techella</i> is also reproduced below.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg-bBToIniLfCzHEA4R2iZVf3kbksi0eCKc7yfJI-XqNzPP4d0pdK9OUSh_rzCfzjfV7DXuvubv0bx8GYkTWJ5LLpL5_5Y1IXpwhS0VNThNsA5Wri6Dw9H5_7zxc5fSROI-2z_tAAHnhmK4ulPq3hWoU8I3uWsahCs1uMH8JSZZyf5I6iksNzaPc1DOXfD/s154/L_bulimoides-Hald-Binney.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="82" data-original-width="154" height="82" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg-bBToIniLfCzHEA4R2iZVf3kbksi0eCKc7yfJI-XqNzPP4d0pdK9OUSh_rzCfzjfV7DXuvubv0bx8GYkTWJ5LLpL5_5Y1IXpwhS0VNThNsA5Wri6Dw9H5_7zxc5fSROI-2z_tAAHnhmK4ulPq3hWoU8I3uWsahCs1uMH8JSZZyf5I6iksNzaPc1DOXfD/s1600/L_bulimoides-Hald-Binney.jpg" width="154" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Hald. <b><span style="color: #783f04;">[6]</span></b> Binney <b><span style="color: #783f04;">[7]</span></b> Hald. <b><span style="color: #783f04;">[8]</span></b></span></td></tr></tbody></table><p>Now I feel quite
confident that a significant fraction of my (admittedly rather specialized)
readership will be at least passingly familiar with the crappy little lymnaeids
we find crawling around on the muddy margins of our rivers, ditches, and ponds
here in the American East. You all
listen up. None of you would ever
confuse a population of lymnaeids bearing shells such as those depicted above
with <i><a href="https://www.fwgna.org/species/lymnaeidae/l_cubensis.html" target="_blank">Lymnaea (Galba) cubensis/viator</a></i>, am I right? The body whorl is way too big. And – good grief – look at the scale bar on
that holotype! Adult <i>L. bulimoides</i> often
reach double-digit shell lengths, whereas none of our crappy little <i>Galba</i>-type
lymnaeids on this side of the Mississippi River ever really do.</p><p>Nevertheless, in 1891 Henry Pilsbry became the first in a
long line of professional malacologists to confuse <i>L. bulimoides</i> with <i>L.
cubensis</i>, in a survey of the malacofauna of the Yucatan peninsula <b><span style="color: #783f04;">[9]</span></b>. He began by synonymizing <i>L. umbilicata</i> C.B.
Adams 1840 under <i>L. cubensis</i> Pfeiffer 1839.
Then he wrote:</p><p></p><blockquote><span style="font-size: x-small;">"The typical <i>cubensis</i> ranges at least as far west as the
Mississippi River and eastern Texas.
West and southwest of this it gives place to <i>L. techella</i> Hald., and <i>L.
bulimoides</i> Lea. The last form may be
considered a geographic race or subspecies of the <i>cubensis</i>. <i>L. techella</i> Hald. is nearly identical with
<i>umbilicata</i>."</span></blockquote><p></p><p>Pilsbry corrected himself, however, in a survey of the
Mollusca of the southwestern states he published with J. H. Ferriss in 1906
<b><span style="color: #783f04;">[10]</span></b>:</p><p></p><blockquote><span style="font-size: x-small;">“<i>Lymnaea techella</i> was formerly considered by one of us to be
a synonym or race of <i>L. cubensis</i> Pfr, and <i>L. bulimoides </i>was treated as a
variety of the same species. They are
certainly very similar, but <i>cubensis</i> has a more triangular and less broadly
developed columellar expansion.”</span></blockquote><p></p><p>Then going beyond a simple resurrection of Isaac Lea’s <i>L.
bulimoides</i>, Pilsbry and Ferriss went on to recognize three subspecies
underneath it: Haldeman’s <i>techella</i> from Texas, New Mexico and Arizona,
Hemphill’s <i>sonomaensis</i> from California, and their own new <i>cockerelli</i>,
widespread in New Mexico, Colorado, Nebraska and South Dakota.</p><p>Everybody look with me now at the three Pilsbry &
Ferriss figures I have reproduced below.
They’re all significantly larger than our crappy amphibious lymnaeids
here in The East, right? The shell
lengths reported by Pilsbry for all (N = 16) specimens he measured of all
subspecies ranged from 8 mm up to a whopping 14 mm, with mean = 10.2 mm, good
grief! Very, very clearly not <i>L.
cubensis</i>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgZD1fXn1AZARaFbq42Y4BFThzgYVeRl_PHFGhHfRH8X-26QB1LpMFy6Q_GCtyWxFPrkqo4ac-RctZPK8PFd1Ped9JDHWzNyRWrkVwvb_3okiutv6QBv3-9DNL4B0PDjLEOuJhgo-aDpWwZGUvyz1AmxUBJ6F3cEt2l7rGhQyICXP1EDf6HSo3fX0BOI035/s3264/Pilsbry-Ferriss-cockerelli.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1727" data-original-width="3264" height="169" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgZD1fXn1AZARaFbq42Y4BFThzgYVeRl_PHFGhHfRH8X-26QB1LpMFy6Q_GCtyWxFPrkqo4ac-RctZPK8PFd1Ped9JDHWzNyRWrkVwvb_3okiutv6QBv3-9DNL4B0PDjLEOuJhgo-aDpWwZGUvyz1AmxUBJ6F3cEt2l7rGhQyICXP1EDf6HSo3fX0BOI035/s320/Pilsbry-Ferriss-cockerelli.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Pilsbry & Ferriss <b><span style="color: #783f04;">[10]</span></b></span></td></tr></tbody></table><p>Pilsbry’s 1906 dabbling with the obscure little lymnaeids of
the American West did not take place in isolation, of course. Indeed, the flood of pulmonate gastropod
descriptions that washed across North America in the mid-nineteenth century
became a torrent in the early twentieth, our hero Frank Collins Baker surfing
high upon its crest. In 1909, Baker <b><span style="color: #783f04;">[11]</span></b>
raised Hemphill’s <i>sonomaensis</i> to the full species level and described <i>Lymnaea
hendersoni</i> from Colorado, a new species “at first thought to be <i>Lymnaea sonomaensis</i>,”
but “differing in the form of the spire and aperture.”</p><p>And in 1911 he published his landmark “Lymnaeidae of
North America, Recent and Fossil <b><span style="color: #783f04;">[12]</span></b>,” placing his own contributions, and those of
his mentor Pilsbry <b><span style="color: #783f04;">[13]</span></b>, into a continental framework. Baker recognized four subspecies of <i>Galba
bulimoides</i>: the typical form restricted to the West Coast (BC, WA, OR, CA),
Haldeman’s<i> techella</i> ranging from California through the desert southwest to
Texas, Oklahoma, and Kansas, and Pilsbry’s <i>cockerelli </i>overlapping both, while
extending further north into Nebraska and The Dakotas. To these he added a new subspecies <i>L.
bulimoides cassi</i> from California, utterly indistinguishable from <i>techella</i> in all
respects, as well as the full species <i>sonomaensis</i> and <i>hendersoni</i>, both indistinguishable from <i>cockerelli</i>.</p><p>Although Baker carefully noted radula morphology when any
observations were available to him throughout his 1911 monograph, he did not
begin to draw a distinction between species bearing bicuspid first laterals and
tricuspid first laterals until 1928 <b><span style="color: #783f04;">[14]</span></b>.
He did note that the radula of <i>G. bulimoides cockerelli </i>bore bicuspid
first lateral teeth, “similar to that of <i>cubensis</i>” in 1911, and that
<i>hendersoni </i>also bore bicuspid first laterals “similar to those of <i>techella</i>,”
but offered no observations on any of the other taxa mentioned above, including
(oddly) <i>techella</i>.</p><p>There is no evidence that F.C. Baker ever confused <i>L.
bulimoides</i>, or any of the <i>bulimoides</i>-related taxa, with <i>L. cubensis</i>, or any
<i>cubensis</i>-related taxa, at any point in his illustrious career. He was keenly alert to even the finest
distinctions in phenotype, and ever ready to recognize new species and
subspecies on that basis. In 1919 he
described a <i>Galba alberta</i> from western Canada, to my eye looking like a dwarfed
<i>elodes</i>, with bicuspid first laterals <b><span style="color: #783f04;">[15]</span></b>.
In 1929 he teamed up with Junius Henderson to describe a <i>Fossaria
perplexa</i> from Washington state <b><span style="color: #783f04;">[16]</span></b>. And
in 1939 he added a fresh subspecies <i>Stagnicola</i> <b><span style="color: #783f04;">[17]</span></b> <i>bulimoides vancouverensis</i>,
distinguishing a strikingly large-bodied population from British Columbia <b><span style="color: #783f04;">[18]</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3526C3HWp1LUJJXv8Givxv6CpyLUbBTRWh5TprPaZ-hORSe-G3Nhh-dOU2NpsQk8-dn7aLuuFPN7JGALlXBn3g4caA0gEA11hc_xInqBKDzN4L0-VBdYwtqM0fj43N4HUJGdMcMaeuMF006IRtrvMRrwJIbFIZ7k9ZjzvxO6Sw_wqZvq8N0PCfXiAsCKW/s2700/LeonardPlate1-detail.jpg" style="margin-left: auto; margin-right: auto;"><span style="font-size: x-small;"><img border="0" data-original-height="2700" data-original-width="1623" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3526C3HWp1LUJJXv8Givxv6CpyLUbBTRWh5TprPaZ-hORSe-G3Nhh-dOU2NpsQk8-dn7aLuuFPN7JGALlXBn3g4caA0gEA11hc_xInqBKDzN4L0-VBdYwtqM0fj43N4HUJGdMcMaeuMF006IRtrvMRrwJIbFIZ7k9ZjzvxO6Sw_wqZvq8N0PCfXiAsCKW/s320/LeonardPlate1-detail.jpg" width="192" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Leonard <b><span style="color: #783f04;">[19]</span></b> Plate 1</span></td></tr></tbody></table><p>In 1959 A. Byron
Leonard published a thorough and influential review of the entire gastropod
fauna of Kansas <b><span style="color: #783f04;">[19]</span></b>. And I feel certain
that he must have had a copy of Baker’s 1911 monograph on his desk, showing the
range of both <i>G. bulimoides techella</i> and <i>G. bulimoides cockerelli</i> extending
through the Jayhawk State. In fact,
Baker listed five localities for <i>techella</i> in Kansas, although none for
<i>cockerelli</i>. Remember that. Baker also (of course) included Kansas within
the ranges of <i><a href="https://www.fwgna.org/species/lymnaeidae/l_humilis.html" target="_blank">G. humilis</a></i> and <i>G. obrussa</i> <b><span style="color: #783f04;">[20]</span></b>, both of which he considered
elements of the continental fauna broadly, but did not consider that the range
of <i>G. cubensis</i> extended as far north as Kansas.</p><p>So, Byron Leonard can be excused for identifying <i>L.
bulimoides techella</i> in Kansas, and not identifying <i>L. cubensis</i>. His Plate 1 is reproduced above, showing what
appears to be an unusually large <b><span style="color: #783f04;">[21]</span></b> <i>L. cubensis/viator </i>shell identified as “<i>L.
bulimoides techella</i>.” This seems to be
a fresh re-emergence of the <i>bulimoides/cubensis</i> confusion independent of
Pilsbry’s 1891 error.</p><p>A third, independent confusion of <i>bulimoides</i> and <i>cubensis
</i>also has its roots in the soil of F.C. Baker but germinated much further
north. Baker provided neither figure nor
radular observations for the <i>Fossaria perplexa</i> he described with Junius
Henderson from Washington state in 1929 <b><span style="color: #783f04;">[16]</span></b>.
But his description (“resembles both <i>parva</i> and <i>dalli</i> … larger than <i>dalli
</i>and smaller than <i>parva</i>”) strongly suggests a synonym of either <i>L. humilis</i> or <i>L.
cubensis/viator</i>. In 1973, however, Arthur
Clarke <b><span style="color: #783f04;">[22]</span></b> reported the discovery of a population of crappy little amphibious
lymnaeids in Alberta bearing shells “identical with type specimens of <i>F.
perplexa</i>” on their backs and radulas with bicuspid first laterals in their
mouths. Since he considered <i>L. cubensis</i>
“subtropical and tropical” in its distribution, Clarke reasoned that <i>perplexa</i>
must be “a hitherto unrecognized morph of the highly variable <i>Lymnaea
bulimoides</i>.”</p><p>And if the shell morphology of <i>L. bulimoides</i> is variable
enough to include a population that looks like <i>L. perplexa</i>, surely we might
also include populations that look like <i>L. alberta</i>, yes? Clarke did not have any original observations
to add in 1973, but on the basis of Baker’s original description of the radula
<b><span style="color: #783f04;">[15]</span></b>, lowered <i>L. alberta</i> to the status of “morph” under <i>L. bulimoides</i> as well
<b><span style="color: #783f04;">[23]</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdeLObxFHBGrwPFNYJjETPjeS11QaQro3QTcfBA1S4gMEv7MxmTPendykPJFOg8K0g00JJf4SVx9M1BhFrxmAkY_VRxcfrTZSNluMTcA3F6xseNhD1j6WqdIbg2Zh5yXnIkJIJoKKFEt0MbIy_K8_d55gm9nqokn4cu-oUEEmWLty4j5-o3z_1KP0WJ8SH/s4724/Clarke-1973-bulimoides.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2573" data-original-width="4724" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdeLObxFHBGrwPFNYJjETPjeS11QaQro3QTcfBA1S4gMEv7MxmTPendykPJFOg8K0g00JJf4SVx9M1BhFrxmAkY_VRxcfrTZSNluMTcA3F6xseNhD1j6WqdIbg2Zh5yXnIkJIJoKKFEt0MbIy_K8_d55gm9nqokn4cu-oUEEmWLty4j5-o3z_1KP0WJ8SH/s320/Clarke-1973-bulimoides.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Clarke's <b><span style="color: #783f04;">[22]</span></b> "morphs" of <i>L. bulimoides</i></span></td></tr></tbody></table><p>With the advent of the 1980s came Jack Burch’s “North
American Freshwater Snails,” destined to enter the holy canon of American
malacology <b><span style="color: #783f04;">[24]</span></b>. Burch recognized seven
subspecies of <i>Fossaria (Bakerilymnaea) bulimoides</i>: the three of Pilsbry
(<i>bulimoides ss</i>, <i>techella</i>, <i>cockerelli</i>), the two added by Clarke (<i>alberta</i>,
<i>perplexa</i>), the <i>vancouverensis </i>added by Baker, and Baker’s <i>hendersoni</i>, which had
heretofore been considered specifically distinct. Burch followed Baker in recognizing
<i>sonomaensis</i> at the species level, but clean forgot Baker's <i>cassi</i>, no big loss. Only <i>techella, cockerelli</i>, and the typical
subspecies were figured for <i>bulimoides</i> in the Burch Bible, plus <i>sonomaensis </i>as a separate species.</p><p>And so it came to pass that in January of 2022 I rendezvoused
with our good friend Bruce Stephen in Lawrence, KS, to review the extensive
freshwater gastropod holdings of the Kansas Biological Survey 1971 – 1981. You might remember Bruce from the
comprehensive survey of historic freshwater gastropod records from Nebraska
<b><span style="color: #783f04;">[25]</span></b> he published back in 2015. Bruce
defended his dissertation, a modern survey of freshwater gastropods across
Nebraska and South Dakota, in 2018.</p><p>Bruce and I spent the week pulling vials of snails out of
metal cabinets on the fourth floor of Haworth Hall on the campus of the
University of Kansas, ultimately reviewing an impressive 642 lots, identifying
14 samples of <i>Lymnaea humilis</i>, 15 samples of <i>L. cubensis/viator</i>, and zero
samples <i>L. bulimoides </i>demonstrating the typical (or “<i>techella</i>”)
morphology. I feel confident that, sitting in these same precincts back in 1959, Byron
Leonard <b><span style="color: #783f04;">[19]</span></b> confused <i>L. cubensis/viator </i>with<i> L. bulimoides techella.</i></p><p>Indeed, Bruce has never confirmed a population of typical <i>L.
bulimoides</i> in Nebraska, or South Dakota, or North Dakota, for that matter. It would appear that the range of <i>L.
bulimoides</i> has been greatly exaggerated, almost certainly by confusion with <i>L.
cubensis</i>.</p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiwre46OQh4GQNEiCGGuR9Aqr6jn-bO4F3p9sCdd8VBQrar74lnP-0DLMTcCk7wYyDFSu-Rqbkou7ZvMme0puqlFX42JSsbB05R5TNGtSOUxsjWHUbKRhOingL8jxMFYBUn5NC_qWa8erLvXbTbCqxN9nDLXG3u-3TXiiaC-RYXMPEMaJOtgdMfE8_G7UBo/s640/Rob-at-KU-2022.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="640" data-original-width="480" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiwre46OQh4GQNEiCGGuR9Aqr6jn-bO4F3p9sCdd8VBQrar74lnP-0DLMTcCk7wYyDFSu-Rqbkou7ZvMme0puqlFX42JSsbB05R5TNGtSOUxsjWHUbKRhOingL8jxMFYBUn5NC_qWa8erLvXbTbCqxN9nDLXG3u-3TXiiaC-RYXMPEMaJOtgdMfE8_G7UBo/w150-h200/Rob-at-KU-2022.jpg" width="150" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Bruce's camera 1/22</span></td></tr></tbody></table>Bruce and I did confirm 5 lymnaeid populations bearing
shells of the <i>cockerelli</i> form in Kansas, with similar populations scattered
through Nebraska and The Dakotas as well.
Did F. C. Baker <b><span style="color: #783f04;">[12]</span></b> confuse <i>L. bulimoides techella </i>with <i>L. bulimoides
cockerelli</i>? We’ll come back to that
question next month.<p></p><p>But returning to the <i>bulimoides/cubensis</i> confusion, and
shifting one state south, to Oklahoma.
GenBank holds just two pair of sequences labeled “<i>bulimoides</i>:” a 16S/CO1
pair from E. A. Remigio <b><span style="color: #783f04;">[26, 27]</span></b> and a 16S/CO1 pair from Wethington & Lydeard
<b><span style="color: #783f04;">[28]</span></b>. The former pair (AF485657 and
AY227367, respectively), from an individual collected in “Oklahoma” (no further
information), are both 99% similar to the big body of sequence data for <i>Galba
cubensis/viator</i> that has accumulated in GenBank over many years.</p>
<p class="MsoNormal">The Remigio sequences were swept up into the 2011 study of
Correa et al. <b><span style="color: #783f04;">[29]</span></b> and the influential 2021 study of Alda et al. <b><span style="color: #783f04;">[30]</span></b>,
prompting both of those sets of authors, and me myself a sinner <b><span style="color: #783f04;">[31]</span></b>, to
hypothesize that <i>bulimoides</i> might be a junior synonym of <i>cubensis/viator </i>in a
pair of posts on this very blog.<span style="mso-spacerun: yes;"> </span>Writing
here today, I feel quite certain that sequences AF485657 and AY227367 were
misidentified at their deposition.<span style="mso-spacerun: yes;"> </span>And I
have added red-font retractions to the bottoms of my blog posts of [<a href="https://fwgna.blogspot.com/2012/08/the-lymnaeidae-2012-fossarine-football.html" target="_blank">7Aug12</a>] and
[<a href="https://fwgna.blogspot.com/2021/07/exactly-3ish-american-galba.html" target="_blank">6July21</a>].</p><p class="MsoNormal">The pair of 16S/CO1 sequences uploaded by Wethington &
Lydeard, EU038315 and EU038362 respectively, are 8.9% and 16.5% different from
the Remigio sequences, respectively, and hence did not get swept up into the
big worldwide surveys of Correa and Alda.
Blasting them against GenBank, however, both return close matches to
sequences obtained from a topotypic population of <i>Lymnaea (Stagnicola) caperata</i>,
deposited by Morningstar et al <b><span style="color: #783f04;">[32]</span></b>: 98 – 99% for 16S and 96-97% for CO1. The only conclusion I think it is safe to
make at present from the negligible DNA data available for <i>bulimoides</i> is that I
am not going any further down this rabbit hole <b><span style="color: #783f04;">[33]</span></b>.</p><p class="MsoNormal">So let us now set the record straight, for all time. <b><i>Lymnaea (Galba) bulimoides</i> is a distinct,
valid biological species, not to be confused with <i>Lymnaea (Galba)
cubensis/viator</i>.</b> <i>Fossaria perplexa</i> Baker
& Henderson 1929 is not a subspecies, synonym or morph of <i>bulimoides</i>, nor
is <i>Galba alberta</i> Baker 1919.</p><p class="MsoNormal">And in conclusion, Brothers and Sisters, I rise to the
pulpit. The confusion and
misunderstanding that has historically surrounded the crappy little amphibious
lymnaeids of western North America is but an extension of a greater darkness
that benights international malacology across five continents, Old World and
New. The figure below is from the 2011
review of neotropical lymnaeids published by Ana Correa and her colleagues <b><span style="color: #783f04;">[35]</span></b>,
as reproduced in my review of [<a href="https://fwgna.blogspot.com/2021/06/the-american-galba-and-french-connection.html" target="_blank">7June21</a>].</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqBYMwj0bfx8eEwYG92AqULwxQFb1QP1y2Q1YjEhuvUF2OcJXliMCCbsCsJiXhmYOwWc0EA6BilJn7AKp6aHQzmudzocY-h1Lvg8-Aypvv5_BrGqv51OnVgd503177mbOSAuoz3EiRV2QFW_Z8BkoRS9-_mTb-U7SrRSnvWEmqaE1GCKHFH6p0fAr9AeOg/s1539/Alda-etal-Look-familiar.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1539" data-original-width="1344" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqBYMwj0bfx8eEwYG92AqULwxQFb1QP1y2Q1YjEhuvUF2OcJXliMCCbsCsJiXhmYOwWc0EA6BilJn7AKp6aHQzmudzocY-h1Lvg8-Aypvv5_BrGqv51OnVgd503177mbOSAuoz3EiRV2QFW_Z8BkoRS9-_mTb-U7SrRSnvWEmqaE1GCKHFH6p0fAr9AeOg/w278-h320/Alda-etal-Look-familiar.jpg" width="278" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Correa et al. <b><span style="color: #783f04;">[33]</span></b></span></td></tr></tbody></table><p class="MsoNormal">Populations of crappy little amphibious lymnaeids identified
as “<i>Galba cousini</i> (Jousseaume, 1887)” are common and widespread in muddy
ditches and ponds on the Pacific side of South America, primarily in Ecuador
and Colombia. Where have you seen snails
bearing shells looking like that before?</p><p class="MsoNormal">All the lymnaeid populations we have discussed in this
overly long essay, and all of those depicted in Ana Correa’s figure above, are
potential hosts for the livestock fluke, <i>Fasciola</i>. In Central and South America, huge
international teams of malacologists and parasitologists have published
mountains of research on the evolutionary relationships among <i>truncatula</i>,
“<i>schirazensis</i>,” <i>cubensis/viator</i> and – yes – <i>cousini</i>. A quick search of GenBank returns 35 hits for
<i>G. cousini</i> alone.</p><p class="MsoNormal">Meanwhile here in the USA, the richest country on earth, the
leader of the free world, we have zero authentic sequences for any population
of our own <i>Lymnaea (Galba) bulimoides</i>, known to be an important host of
livestock fluke across the Pacific Northwest since 1929 <b><span style="color: #783f04;">[36]</span></b>. We have four spurious mtDNA sequences from two crappy snails, both of which I think were
misidentified.</p><p class="MsoNormal">United States malacology had a two-generation head start on
South American malacology. Lea (1841)
trumps Jousseaume (1887) by 46 years. I
do not know how we have fallen so far behind the rest of the world today, but I
do know a continent-scale mess when I see it, and international embarrassment
when I feel it. <b>Malacologists of America,
we must do better</b>.</p><p class="MsoNormal"><br /></p><p class="MsoNormal"><u>Notes</u>:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Although pioneered for foot traffic as early as 1811,
the Oregon Trail did not become passable by wagon until the 1830s.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> For a brief biography of “The Nestor of American
Naturalists,” see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Isaac Lea Drives Me Nuts [<a href="https://fwgna.blogspot.com/2019/11/isaac-lea-drives-me-nuts.html" target="_blank">5Nov19</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Lea, I (1841) On fresh water and land shells
(continued). Proceedings of the American
Philosophical Society 2(17): 30 – 34.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Lea, I. (1844/46) Continuation of Mr. Lea’s paper on
fresh water and land shells.
Transactions of the American Philosophical Society 9(1): 1 – 31.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> The U.S. / Canadian boundary in the Pacific Northwest
was not established until 1846.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Haldeman, S.S. (1844) A monograph of the freshwater
univalve Mollusca of the United States, Number 7 Philadelphia: Cary & Hart, Dobson, and
Pennington. 32 pp, 4 plates.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Binney, W.G. (1865) Land and fresh water shells of North
America Part II, Pulmonata Limnophila and Thalassophila. Smithsonian
Miscellaneous Collections 143: 1 – 161.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Haldeman, S.S. 1867
Description of a new species of <i>Limnaea</i>.
American Journal of Conchology 3: 194.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> Pilsbry, H.A. 1891 Land and Fresh-water mollusks
collected in Yucatan and Mexico.
Proceedings of the Academy of Natural Sciences of Philadelphia 43: 310 –
334.</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Pilsbry, H.A. and J.H. Ferriss (1906) Mollusca of the southwestern states II. Proceedings of the Academy of Natural
Sciences of Philadelphia 58: 123 – 175.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Baker, F.C. (1909) A new species of <i>Lymnaea</i>. The Nautilus 22: 140 – 141.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> Baker, F.C. (1911) The Lymnaeidae of North and Middle
America, Recent and Fossil. Chicago
Academy of Sciences, Special Publication Number 3. 539 pp.
For a brief biography of our hero, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The Legacy of Frank Collins Baker [<a href="https://fwgna.blogspot.com/2010/02/legacy-of-frank-collins-baker.html" target="_blank">20Nov06</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> For an exploration of the relationship between Frank
Collins Baker and Emperor Henry Augustus Pilsbry, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The Emperor, the Non-child, and the Not-short Duct [<a href="https://fwgna.blogspot.com/2021/02/the-emperor-non-child-and-not-short-duct.html" target="_blank">9Feb21</a>]</li><li>Dr. Henry A. Pilsbry was a jackass [<a href="https://fwgna.blogspot.com/2021/01/dr-henry-pilsbry-was-jackass.html" target="_blank">26Jan21</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[14] </span></b>Baker, F.C. (1928) Freshwater Mollusca of Wisconsin,
Part I, Gastropoda. Bull. Wisc. Geol. Natur. Hist. Survey, no. 70. Madison:
University of Wisconsin Press. Baker
proposed <i>Nasonia</i> as a subgenus to distinguish species of <i>Fossaria</i> with bicuspid
lateral teeth, but alas, that name was preoccupied. The German malacologist W. K. Weyrauch
proposed the name “<i>Bakerilymnaea</i>” as a substitute in 1964.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> Baker, F.C. (1919) Fresh-water mollusca from Colorado
and Alberta. Bulletin of the American
Museum of Natural History 41(13): 527 – 539.</p><p class="MsoNormal"><b><span style="color: #783f04;">[16] </span></b>Baker, F.C. and J. Henderson (1929) <i>Fossaria perplexa</i>
F. C. Baker and Junius Henderson.
Nautilus 42(3): 103-104.</p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> That's right, F. C. Baker himself transferred <i>bulimoides</i> from the genus <i>Galba/Fossaria</i> to the genus <i>Stagnicola</i>, simply because he discovered a population that was unusually large-bodied. <b>There is absolutely no biological basis for recognizing genus (let alone subgenus) divisions in the worldwide Lymnaeidae</b>. None. The FWGNA follows Hubendick in assigning essentially all lymnaeids to a single vanilla genus <i>Lymnaea</i>. We add subgenera for their indexing function only - just to help the Google machine find our research. For more, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The Classification of the Lymnaeidae [<a href="https://fwgna.blogspot.com/2006/12/classification-of-lymnaeidae.html" target="_blank">28Dec06</a>] </li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> Baker, F.C. (1939) <i>Stagnicola bulimoides vancouverensis</i>
nov. var. The Nautilus 52(4): 144.</p><p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> Leonard, A.B. (1959) Handbook of Gastropods in Kansas.
Miscellaneous Publications of the University of Kansas Museum of Natural
History 20: 1 – 224.</p><p class="MsoNormal"><b><span style="color: #783f04;">[20] </span></b><i>Lymnaea (Galba) obrussa</i> Say 1825 is a junior synonym of
<i>Lymnaea humilis</i> Say 1822. See:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Exactly 3ish American Galba [<a href="https://fwgna.blogspot.com/2021/07/exactly-3ish-american-galba.html" target="_blank">6July21</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[21]</span></b> The scale on Leonard’s entire Plate 1 is dubious. He stated, “figures enlarged approximately 2
times natural size,” but I do not know the original size of the printed
page. I’m working from a pdf.</p><p class="MsoNormal"><b><span style="color: #783f04;">[22]</span></b> Clarke, A. (1973) The freshwater molluscs of the
Canadian Interior Basin. Malacologia, 13, 1-509</p><p class="MsoNormal"><b><span style="color: #783f04;">[23]</span></b> The radula of<i> Lymnaea (Stagnicola) elode</i>s also bears
bicuspid first marginals. I do not agree
with Clarke about the synonymy of <i>L. alberta</i>, but am loathe to digress
further. It clearly is not
<i>bulimoides</i>. That's the point.</p><p class="MsoNormal"><b><span style="color: #783f04;">[24]</span></b> This is a difficult work to cite. J. B. Burch's North American Freshwater
Snails was published in three different ways.
It was initially commissioned as an identification manual by the US EPA
and published by that agency in 1982. It
was also serially published in the journal Walkerana (1980, 1982, 1988) and
finally as stand-alone volume in 1989 (Malacological Publications, Hamburg,
MI).</p><p class="MsoNormal"><b><span style="color: #783f04;">[25]</span></b> Stephen, B. J. (2015)
Species composition of Nebraska’s freshwater gastropod fauna: A review
of historical records. American
Malacological Bulletin 33: 61 – 71. For a review, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Cornhusker Freshwater Gastropods [<a href="https://fwgna.blogspot.com/2015/05/cornhusker-freshwater-gastropods.html" target="_blank">11May15</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[26] </span></b>Remigio, E.A. and Hebert, P.D. (2003) Testing the utility
of partial COI sequences for phylogenetic estimates of gastropod
relationships. Mol. Phylogenet. Evol. 29
(3), 641-647.</p><p class="MsoNormal"><b><span style="color: #783f04;">[27]</span></b> Remigio,E.A. (2002) Molecular phylogenetic relationships in
the aquatic snail genus <i>Lymnaea</i>, the intermediate host of the causative agent
of fascioliasis: insights from broader taxon sampling, Parasitol. Res. 88 (7),
687-696</p><p class="MsoNormal"><b><span style="color: #783f04;">[28]</span></b> Wethington, A.R., & C. Lydeard (2007) A molecular
phylogeny of Physidae (Gastropoda: Basommatophora) based on mitochondrial DNA
sequences. Journal of Molluscan Studies
73: 241 - 257.</p><p class="MsoNormal"><b><span style="color: #783f04;">[29]</span></b> Correa, A.C., J.S. Escobar, O. Noya, L.E. Velasquez, C.
Gonzalez-Ramirez, S. Hurtrez-Bousses & J-P. Pointier (2011) Morphological and molecular characterization
of Neotropic Lymnaeidae (Gastropoda: Lymnaeoidea), vectors of fasciolosis. Infection, Genetics and Evolution 11:
1978-1988. I reviewed that paper in my
post:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The Lymnaeidae 2012: Fossarine Football [<a href="https://fwgna.blogspot.com/2012/08/the-lymnaeidae-2012-fossarine-football.html" target="_blank">7Aug12</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[30]</span></b> Alda, Pilar, M. Lounnas, A.Vázquez, R. Ayaqui, M.
Calvopiña, M. Celi-Erazo, R.T. Dillon Jr., L. González Ramírez, E. Loker, J. Muzzio-Aroca, A. Nárvaez, O.
Noya, A. Pereira, L. Robles, R. Rodríguez-Hidalgo, N. Uribe, P. David, P.
Jarne, J-P. Pointier, & S. Hurtrez-Boussès (2021) Systematics and
geographical distribution of <i>Galba</i> species, a group of cryptic and world-wide
freshwater snails. Molecular
Phylogenetics and Evolution 157: 107035. [<a href="https://www.fwgna.org/dillonr/Alda-etal-2021.pdf" target="_blank">pdf</a>] [<a href="https://www.sciencedirect.com/science/article/abs/pii/S1055790320303079" target="_blank">html</a>] I reviewed that paper in my post:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Exactly 3ish American Galba [<a href="https://fwgna.blogspot.com/2021/07/exactly-3ish-american-galba.html" target="_blank">6July21</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[31]</span></b> I speculated that <i>L. bulimoides </i>might be a junior
synonym of <i>L. cubensis/viator</i> in both of the blog posts cited above. But in my own defense, see my footnote #11 of
6July21: “I am quite certain, however, that the single 16S sequence uploaded to
GenBank by Remigio, labeled “<i>Fossaria bulimoides</i>” but collected 2,000 miles
from the <i>bulimoides</i> type locality in Oregon, is weak evidence, indeed.”</p><p class="MsoNormal"><b><span style="color: #783f04;">[32]</span></b> Morningstar,C.R., Inoue,K., Lang,B.K. and
Berg,D.J. (2018) A comprehensive status,
phylogenetic, and anatomical review of <i>Stagnicola caperata</i> (Say, 1829) in the
south-west United States. Aquatic Conservation 28 (3), 527-534.</p><p class="MsoNormal"><b><span style="color: #783f04;">[33]</span></b> OK, maybe a little further. Our good friend Amy Wethington tells me that
she got her sequences from Rob Guralnick, who got them from a Mesa County,
Colorado sample identified as <i>Lymnaea bulimoides </i>by Shi-Kuei Wu. Shi-Kuei was a careful worker, and thumbing
through his (admirable) Colorado Inventory <b><span style="color: #783f04;">[34] </span></b>I find no evidence that he was
confused about the identity of <i>L. bulimoides</i>.
I have no idea what happened here.
Classic GenBank SNAFU.</p><p class="MsoNormal"><b><span style="color: #783f04;">[34]</span></b> Wu, S-K. (1989) Colorado Freshwater Mollusks. Natural
History Inventory of Colorado, no. 11. Boulder: Univ. Colorado Museum.</p><p class="MsoNormal"><b><span style="color: #783f04;">[35]</span></b> Correa, A.C., J.S. Escobar, O. Noya, L.E. Velasquez, C.
Gonzalez-Ramirez, S. Hurtrez-Bousses & J-P. Pointier (2011) Morphological and molecular characterization
of Neotropic Lymnaeidae (Gastropoda: Lymnaeoidea), vectors of fasciolosis. Infection, Genetics and Evolution 11:
1978-1988.</p><p class="MsoNormal"><b><span style="color: #783f04;">[36]</span></b> Shaw, J.N. and Simms, B.T. 1929. <i>Galba bulimoides</i> Lea
an intermediate host of <i>Fasciola hepatica</i> in Oregon. Science 69: 357.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-6954846439719265532024-01-09T11:12:00.003-05:002024-03-03T21:51:43.312-05:00Three New Fontigens From Virginia<p><span style="font-size: x-small;">Editor's Note - This essay was previously published as: Dillon, R. T., Jr. (2023b) Three new <i>Fontigens</i> from Virginia. pp 225 - 232 <b>in</b> The Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other Essays</i>. <a href="https://fwgna.org/publications/" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>The most faithful and attentive subset of my readership
might perhaps remember an essay I posted a year ago this past August [<a href="https://fwgna.blogspot.com/2022/08/startled-by-fontigens-sort-of-i-suppose.html" target="_blank">9Aug22</a>],
wherein I reviewed the four-year journey that ultimately led to the
confirmation of a <i><a href="https://www.fwgna.org/species/hydrobiidae/f_cryptica.html" target="_blank">Fontigens cryptica</a></i> population inhabiting interstitial spaces
in the karstland of central Kentucky <b><span style="color: #783f04;">[1]</span></b>.
Here is a detail that I cannot imagine any of you could possibly
remember, no matter how attentive you have been. About halfway through that essay I mentioned
that two of the <i>Fontigens</i> samples Hsiu-Ping Liu sequenced for our big mtDNA
gene tree were contributed by “our good friends Wil Orndorff and Tom Malabad of
the VaDCR."</p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiI73VMHzAmq-3udwaZUIt46Z-udqj-PQq1Oq1QvEI2llKD3SydKoHJef5LZ1XBjN-PihNH5uBcaqFH10FW9aOxDja21d4iGkk5dIDBKoxZio4keE3zfRvUhpazH4ZnM2DjFiBFGUKHjSqKSsutDJcJHwm40daIgSQMFDChrLxrRJarIvnhVxNqqNzFPuOE/s508/LaneCave18-trim.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="508" data-original-width="422" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiI73VMHzAmq-3udwaZUIt46Z-udqj-PQq1Oq1QvEI2llKD3SydKoHJef5LZ1XBjN-PihNH5uBcaqFH10FW9aOxDja21d4iGkk5dIDBKoxZio4keE3zfRvUhpazH4ZnM2DjFiBFGUKHjSqKSsutDJcJHwm40daIgSQMFDChrLxrRJarIvnhVxNqqNzFPuOE/w166-h200/LaneCave18-trim.jpg" width="166" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Lane Cave (<i>F. hershleri</i>)</span></td></tr></tbody></table>
<p class="MsoNormal">Now let me highlight a blessing of the sort I have found
gratifyingly common throughout my 40-year professional career, of which I
should be more thankful, but which I fear I have often taken for granted.<span style="mso-spacerun: yes;"> </span>Completely independent of the <i>Fontigens
cryptica</i> research project that Lori Schroeder and I kept on a slow burner in
Kentucky from 2017 – 2021, in November of 2018 I received a cordial email from
my old friend Wil Orndorff <b><span style="color: #783f04;">[2]</span></b>, with the subject line “Some Virginia cave and
spring snail collections that need you.”<span style="mso-spacerun: yes;">
</span>And after a bit of negotiation, a big box containing 61 tiny plastic
vials arrived with a thump on my front porch.<span style="mso-spacerun: yes;">
</span>The even-tinier gastropod samples enclosed in those 61 tiny vials had
been collected by VaDCR Natural Heritage from caves and cave springs all over
the Old Dominion, 1998 – 2018.<span style="mso-spacerun: yes;"> </span>Holy
crap, I replied to Wil.<span style="mso-spacerun: yes;"> </span>N=61 is not
“some.”</p><p class="MsoNormal">A bit daunted, perhaps, but undeterred, I went to work
sorting and identifying Wil’s very large sample of very tiny snails, a process
that stretched four months, into March of 2019.
Of the 61 samples, 30 contained only land snails, and 11 contained only
freshwater gastropods typical of above-ground habitats: pleurocerids, physids,
and so forth. That left a (still
remarkable) 20 samples of hydrobioid cave snails on my lab bench.</p><p class="MsoNormal">Of all 7,999,999,999 people alive in this world today who
have not pulled a fire alarm at the Academy of Natural Sciences of Philadelphia
in the middle of the night <b><span style="color: #783f04;">[3]</span></b>, I flatter myself that I have developed the
keenest eye for <i>Fontigens</i>. Those 20
samples included 11 of <i><a href="https://www.fwgna.org/species/hydrobiidae/f_orolibas.html" target="_blank">F. orolibas</a></i>, 3 of <i><a href="https://www.fwgna.org/species/hydrobiidae/f_bottimeri.html" target="_blank">F. bottimeri</a></i>, 2 of <i><a href="https://www.fwgna.org/species/hydrobiidae/f_morrisoni.html" target="_blank">F. morrisoni</a></i>, 2
<i><a href="https://www.fwgna.org/species/hydrobiidae/h_unthanksensis.html" target="_blank">Holsingeria</a></i>, and 2 samples of hydrobioid cave snails unlike any I had ever seen
before.</p><p class="MsoNormal">From the Sugar Run Cave System of Giles County, Virginia,
(draining west into the New -> Ohio) I found a single sample of 14
individual <i>Fontigens</i> bearing strikingly ovoid shells – much more convex in
their outline than any I had ever seen, bearing a depressed apex. And from Lane Cave in Scott County, Virginia,
(draining south into the Clinch -> Tennessee) I found a singleton hydrobioid
snail that looked more like an <i>Amnicola</i> or a <i>Lyogyrus</i> than a <i>Fontigens</i>. I left those two lots unidentified in the
spreadsheet I sent to Wil on 1Mar19. And
here is how I closed my email: “After I die, if I’m reincarnated <b><span style="color: #783f04;">[4]</span></b> as the
second Bob Hershler, I’ll take another look at these. Not before.”</p><p class="MsoNormal">So two months later, Lori Schroeder and Andrew Berry
discovered one single putative <i>F. cryptica </i>living under a rock at a springhead
in the Bernheim Forest of central Kentucky [<a href="https://fwgna.blogspot.com/2019/07/finding-fontigens-cryptica.html" target="_blank">3July2019</a>]. And fight it though I most certainly had for
years, I found myself in the <i>Fontigens</i> business. I contacted Hsiu-Ping Liu out in Denver and
prevailed over her to join Lori, Andrew and me in a grant proposal, then set
out on that <i>Fontigens</i>-themed tour of the Great Valley of Virginia I described
in my essay of last August [<a href="https://fwgna.blogspot.com/2022/08/startled-by-fontigens-sort-of-i-suppose.html" target="_blank">9Aug22</a>], upon my return promptly posting my large
sample of tiny snails off to Hsiu-Ping for sequencing.</p><p class="MsoNormal">And included among all those control samples of <i><a href="https://www.fwgna.org/species/hydrobiidae/f_nickliniana.html" target="_blank">F. nickliniana</a></i> and <i>F. orolibas</i> and <i>F. morrisoni</i> and <i>F. bottimeri</i> were, quoting now
from my email to Hsiu-Ping of 17July19 …</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">…two extra samples at the bottom of my spreadsheet, labelled
“xtr1” and “xtr2.” I think I told you
that Wil Orndorff and our colleagues at the Va-DCR sent me a big shipment of
cave snails last fall, from all over Virginia.
Included in that shipment were two samples I absolutely could not
identify, one from Sugar Run Cave in Giles County, the other from Lane Cave in
Scott County. Obviously, these are very
low priority. But if, in the
(increasingly unlikely) event we had a bit of money left over… my colleagues
and I would be most gratified.</span></blockquote><p></p><p class="MsoNormal">The first results came back from Hsiu-Ping in late August of
2019 – an early version of that gene tree I shared with you all on
[<a href="https://fwgna.blogspot.com/2022/08/startled-by-fontigens-sort-of-i-suppose.html" target="_blank">9Aug22</a>]. And we were immediately
impressed by the tremendous interpopulation CO1 sequence divergence within our
control species which, you will recall, ended up being the headline of the
paper we ultimately published in 2021 <b><span style="color: #783f04;">[1]</span></b>.
But the intraspecific variance did not swamp out the sequence variation
among species, which ranged from a bit less than 9% up to a bit more than 20%. And the mean sequence divergence between three
snails sampled from the Sugar Run Cave System and their nearest genetic
neighbor (<i>F. morrisoni</i>) was 9.0%, and that between our singleton from Lane Cave
and its nearest neighbor (one of the <i>F. nickliniana</i> populations) was 13.2%,
strongly supporting the specific status of both those “xtr” populations.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgv5xvLrH4vRJ-V7sAkWenU9yURSBxTlc1UWj2ldGmlX_aiQkbcrRJAZ0GQVyZgBXB6p_gr_XqZTtKa77icvr5xMuwXaWoll-Rq_LTzbVLTQXAWx8JhmFtMfumMQFs9iWVPX7IOQVFVD-ChyUiSiBn43hrKN658HC8gnoDUV4eLV0XLEoAvBpR-4IK9Pl01/s2209/SugarRunCave-trim.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1658" data-original-width="2209" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgv5xvLrH4vRJ-V7sAkWenU9yURSBxTlc1UWj2ldGmlX_aiQkbcrRJAZ0GQVyZgBXB6p_gr_XqZTtKa77icvr5xMuwXaWoll-Rq_LTzbVLTQXAWx8JhmFtMfumMQFs9iWVPX7IOQVFVD-ChyUiSiBn43hrKN658HC8gnoDUV4eLV0XLEoAvBpR-4IK9Pl01/s320/SugarRunCave-trim.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Sugar Run Cave (<i>F. benfieldi</i>)</span></td></tr></tbody></table><p class="MsoNormal">Again, I must emphasize.
I would never dream of looking for new species on a gene tree. But I brought a hypothesis with me to the
analysis that Hsiu-Ping so ably executed in August of 2019, arising from my
understanding of the biology of the organisms I was studying. I predicted that the Lane Cave and Sugar Run
populations might represent heretofore undiscovered species of <i>Fontigens</i>. And testing that hypothesis with a gene tree,
I found that it was supported.</p><p class="MsoNormal">And so, I surrendered to the inevitability that I myself
would be duty-bound to describe a couple new species of <i>Fontigens</i> in this life,
rather than the next. So, on 29Aug19 I
wrote to Wil & Tom:</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">“Do you have any plans to return to either Lane Cave or
Sugar Run Cave any time soon? We really
need more snails. If you could find a
decent sample size (I would love N = 30) I myself would be game to dissect them
and describe them formally. I’m not Bob
Hershler, so need a bunch of extras, so I can screw up. Species descriptions are not my forte, but it
needs to be done, and I don’t know anybody else who could do it.”</span></blockquote><p></p><p class="MsoNormal">The answer turned out to be an enthusiastic yes. It materialized that over the previous nine
months, Wil and Tom had continued to stomp all over the Commonwealth, lowering
themselves upside down into every hole large enough to lose a basketball,
scouring the inner recesses of the Old Dominion for <i>Fontigens</i>. Although they had not revisited either Lane
Cave or the Sugar Run Cave System by that point, they had already collected 12
fresh samples, which they were pleased to send me in September of 2019. And in February of 2020, yet another fresh
batch of 10 <i>Fontigens</i> samples arrived on my doorstep, this one including N = 3
from Lane Cave, N = 18 from the Sugar Run Cave System, and N = 39 from a new
sampling location, Dulaney’s Cave, which turned out to be the most interesting
of all.</p><p class="MsoNormal">At this point, a boxed essay on the environments from which
these populations were sampled might be helpful. Lane Cave is developed in Cambrian Marysville
Limestone atop a bluff running parallel to Copper Creek of the Clinch River
drainage, a tributary of the Tennessee.
The cave is a not-insubstantial 0.8 km long and about 60 m deep. The stream running through it seems to be fed
by multiple, small surface sinks at the top of the bluff, and apparently
resurges at a spring tributary to Copper Creek.</p><p class="MsoNormal">The Sugar Run Cave system, 170 km northeast, is much larger
and more complicated. Developed 200 m deep in Ordovician limestone on the
northeast flank of Sugar Run Mountain, the system includes at least 45 km of
passages, multiple streams and multiple entrances, the relationships among
which are poorly understood. The sample
that Tom & Wil sent me in February labeled “Dulaneys Cave” came from
waters connected to subterranean Sugar Run through some unknown passage, all of
which ultimately drains into Walker Creek of the New (-> Ohio) River system.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg2WibFem2LNAbRve-5rKuuJg5FBWXmzcISH69cGjWbWY1_q5aOPtOjv1upW4PL4GdlJHVAm18oECSxeydDZWlxNM73xQUwBKq1LDGBLCDKwVh5b25a7vVvxqP4QZk1hLS2VBBdguc7KYvCM2z2KfSLcvOp__YqsXwiTItA6vAr7-UHkPCtL0ZpM6FLiNRu/s2453/dulaneys-elongate.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1840" data-original-width="2453" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg2WibFem2LNAbRve-5rKuuJg5FBWXmzcISH69cGjWbWY1_q5aOPtOjv1upW4PL4GdlJHVAm18oECSxeydDZWlxNM73xQUwBKq1LDGBLCDKwVh5b25a7vVvxqP4QZk1hLS2VBBdguc7KYvCM2z2KfSLcvOp__YqsXwiTItA6vAr7-UHkPCtL0ZpM6FLiNRu/s320/dulaneys-elongate.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Dulaney's Cave, elongate (<i>F. davisi</i>)</span></td></tr></tbody></table><p class="MsoNormal">And when I dumped that little plastic vial labeled
“Dulaneys” into a dish under my dissecting scope, my eyes were met by quite the
unexpected sight.</p><p class="MsoNormal">Yes, I counted N = 31 of those strange <i>Fontigens</i> bearing the
unique ovoid shells I had previously seen in the Sugar Run samples. But plopped right in the middle of those 31
were N = 8 individuals of what looked like yet another species of <i>Fontigens</i> – a
third one – I had never seen before.
These bore shells that were larger, and darker, and elongate/pupoid in
overall outline. Good grief!</p><p class="MsoNormal">So I started my dissections.
And of course, after each dissection I saved all the tissues for
sequencing. And in March of 2020 I
pitched Hsiu-Ping on the possibility of a second project, beyond the <i>Fontigens
cryptica</i> project to which we were already obligated, describing three new
<i>Fontigens</i> species from Virginia.</p><p class="MsoNormal">Well, by that point pretty much all the college campuses
nationwide were in the grip of the Coronavirus panic. But Hsiu-Ping, bless her heart, moved her lab
into the basement of her private home, and with perhaps even less distraction
than she might have otherwise suffered in an ordinary spring semester, was
happy to collaborate. </p><p class="MsoNormal">And in so in May of 2020 I sent Hsiu-Ping two fresh samples
of the Lane Cave unknown, three from Sugar Run, and three from Dulaney
Cave. I told her that the Dulaney sample
looked like two different shell phenotypes to me, elongate and ovoid, although
I didn’t tell her which tubes held which phenotype. And by that point I was aware of the
anatomical similarity between the Dulaney/Sugar Run snails and <i>Fontigens
orolibas</i>. So I also sent her a fresh
control sample of <i>F. orolibas</i> from nearby Tawney’s Cave <b><span style="color: #783f04;">[5]</span></b> as well.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsO0VUA7_r6YdYjfBIOaGkuCISquvhR_lJfnD0Vaf96ZvNMZ3cPVelQQgafvmno-A9Ppik6Oj9Kc08ttDDvUS24_oqB7ZJv54CFeDOvHKkB9oWFOB1J-TtbbbP_h3s16aWLpvMZb5ZSUYyK5TxCjm0Njlou3YwLE44nBmdseBV9TfkcH8XRzUNvaPvaJS-/s2327/Dillon-etal-fig1-abbrev.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2327" data-original-width="1919" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsO0VUA7_r6YdYjfBIOaGkuCISquvhR_lJfnD0Vaf96ZvNMZ3cPVelQQgafvmno-A9Ppik6Oj9Kc08ttDDvUS24_oqB7ZJv54CFeDOvHKkB9oWFOB1J-TtbbbP_h3s16aWLpvMZb5ZSUYyK5TxCjm0Njlou3YwLE44nBmdseBV9TfkcH8XRzUNvaPvaJS-/s320/Dillon-etal-fig1-abbrev.jpg" width="264" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Baysian Tree abbreviated from <span style="color: #783f04;"><b>[6]</b></span></span></td></tr></tbody></table><p class="MsoNormal">The CO1 gene tree above is an abridged version of the tree
Hsiu-Ping sent me in March of 2021, showing just one individual per
population. The full-featured model,
which you can see in the Appendix of Volume 5 <b><span style="color: #783f04;">[6]</span></b>, was based on N = 47 individual
<i>Fontigens</i>, including 3 individuals from Lane Cave, 6 from Sugar Run, 2
Dulaneys-elongate, 1 Dulaneys-ovoid, and 2 from the control <i>orolibas </i>at
Tawney’s Cave. Most of the data (shown
in black) were borrowed from the <i>F. cryptica</i> study of Liu et al <b><span style="color: #783f04;">[1]</span></b> published
in 2021. The sequences in blue are new.</p><p class="MsoNormal">Marked in red are the minimum sequence divergences between
each of our three putatively new species and its nearest neighbor, all greater
than the minimum intraspecific distance we set in our 2021 paper.</p><p class="MsoNormal">The bottom line was just published last month as an appendix to
FWGNA Volume 5, by Dillon, Malabad, Orndorff and Liu <b><span style="color: #783f04;">[6]</span></b>. The two new <i>Fontigens</i> species from the Sugar
Run / Dulaney system are both members of the <i>orolibas</i> group, bearing a
tripartite penis with one tubular and one bulbous accessory gland. The bodies and eyespots of both species are
unpigmented. I was pleased to name the
population bearing ovoid shells for Dr. Ernest F. (Fred) Benfield, my
undergraduate mentor at Virginia Tech <b><span style="color: #783f04;">[7]</span></b>, and the population bearing elongate
shells for Dr. George M. Davis, my graduate mentor at the ANSP <b><span style="color: #783f04;">[8]</span></b>.</p><p class="MsoNormal">The Lane Cave <i>Fontigens</i> is a member of the <i>nickliniana</i>
group, its tripartite penis bearing two tubular glands. Its body and eye spots are pigmented. These observations, together with the fact
that our collections arrived in a mixture with juvenile above-ground-dwelling
<i><a href="https://www.fwgna.org/species/pleuroceridae/g_simplex.html" target="_blank">Pleurocera simplex</a></i> (Say), suggest to us that the Lane Cave <i>Fontigens</i> might be
capable of living in surface waters.
This new species I was gratified to name in honor of my buddy, Bob <b><span style="color: #783f04;">[3]</span></b>.</p><p class="MsoNormal"> </p>
<p class="MsoNormal"><u>Notes</u>:<o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Liu, H-P., L. Schroeder, A. Berry, and R.T. Dillon, Jr.
(2021) High levels of mitochondrial DNA sequence divergence among isolated
populations of <i>Fontigens</i> (Truncatelloidea: Emmericiidae) in eastern USA.
Journal of Molluscan Studies 87. [<a href="https://www.fwgna.org/dillonr/Liu-etal-2021.pdf" target="_blank">pdf</a>]
[<a href="https://academic.oup.com/mollus/article/87/3/eyab026/6354584?login=false" target="_blank">html</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> You might remember Wil as the leader of that expedition
I undertook into Unthanks Cave way back in 2007, as described in:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Cave Snail Adventure [<a href="https://fwgna.blogspot.com/2007/08/cave-snail-adventure.html" target="_blank">12Aug07</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> For a review of the professional contributions of Dr.
Robert Hershler, together with a well-curated anecdote or two more personal in
their nature, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>My Buddy Bob [<a href="https://fwgna.blogspot.com/2022/07/my-buddy-bob.html" target="_blank">6July22</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> To be very clear, I am a Presbyterian. If I find myself reincarnated as anything –
be it cow, bug, malacologist or Methodist – I shall be most disappointed.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Two of our previous <b><span style="color: #783f04;">[1]</span></b> <i>orolibas</i> populations (including
the topotypes) came from Atlantic drainages, and the third was from a Tennessee
drainage. So since the Sugar Run Cave
system drains toward the New River, we felt as though a fourth <i>orolibas</i> control
(Tawney’s Cave) was necessary.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Dillon, R.T., Jr., T.E. Malabad, W.D. Orndorff &
H-P. Liu (2023) Three new <i>Fontigens</i> (Caenogastropoda: Fontigentidae) from caves
in the Appalachian Ridge and Valley Province, Virginia. Pp. 283 - 306 <b>in</b>
Dillon, R.T., Jr. et al. <i>The Freshwater Gastropods of North America Volume V:
Ohio, Cumberland, and Tennessee River Systems</i>. FWGNA Press, Charleston. [<a href="https://www.fwgna.org/dillonr/Dillon-Malabad-Orndorff-Liu.pdf" target="_blank">pdf</a>] <b>Order your copies today!</b></p><p class="MsoNormal"></p><ul style="text-align: left;"><li>FWGNA Volumes 5, 6, and 7 Now Available! [<a href="https://fwgna.blogspot.com/2023/12/fwgna-volumes-5-6-and-7-now-available.html" target="_blank">6Dec23</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Fred Benfield made cameo appearances in my essay of <a href="https://fwgna.blogspot.com/2023/04/growing-up-with-periwinkles.html" target="_blank">6Apr23</a> (Growing Up With Periwinkles) and in my essay of [<a href="https://fwgna.blogspot.com/2014/05/to-identify-physa-1975.html" target="_blank">6May14</a>], (To Identify a Physa,
1975). Look at footnote #16 of the 2014
essay for a sample of Fred's memorable advice.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> George Davis costarred with Steve Ahlstedt in my essay of <a href="https://fwgna.blogspot.com/2022/04/the-ham-cheese-and-lithasia-jayana.html" target="_blank">5Apr22</a> (The Ham,
the Cheese, and Lithasia jayana) and made cameo appearances in [<a href="https://fwgna.blogspot.com/2022/03/no-reproductive-isolation-between.html" target="_blank">28Mar22</a>], [<a href="https://fwgna.blogspot.com/2019/03/pleurocera-shenandoa-nsp.html" target="_blank">11Mar19</a>],
and [<a href="https://fwgna.blogspot.com/2010/07/crisis-at-lake-waccamaw.html" target="_blank">16July10</a>].</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-2028554294717540302023-12-06T08:08:00.006-05:002023-12-06T08:13:35.583-05:00FWGNA Volumes 5, 6, and 7 Now Available!<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwtCeHfedafxHeTfOsu0BNMIA5kMktaFf4uwks4fJdgmSZH4o1rvrqJW0q0Tt4lVPTsQ9gpFpc9ez1APetr7nbU-QgAJBJ50ShIlJ7aBBdHYfoI2kkxZeu-oEPcfdk7QOJlSHEjDf0nxNX1jfvRwQ9NxCxx6E6aAtSj0By0B3DZb6akvUMAmbwI-lM-CV3/s2559/Vol5-front-cover.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="2559" data-original-width="1691" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwtCeHfedafxHeTfOsu0BNMIA5kMktaFf4uwks4fJdgmSZH4o1rvrqJW0q0Tt4lVPTsQ9gpFpc9ez1APetr7nbU-QgAJBJ50ShIlJ7aBBdHYfoI2kkxZeu-oEPcfdk7QOJlSHEjDf0nxNX1jfvRwQ9NxCxx6E6aAtSj0By0B3DZb6akvUMAmbwI-lM-CV3/w132-h200/Vol5-front-cover.jpg" width="132" /></a></div>It is our great pleasure to announce the publication of
Volumes 5, 6, and 7 in the Freshwater Gastropods of North America series, now
extending FWGNA coverage from U.S. Atlantic drainages into the Ohio, Cumberland
and Tennessee River systems of the American interior. These three important new references,
essential for the libraries of malacologists, aquatic biologists and natural
resource managers with interests anywhere in the East, are now available at a
substantial discount directly from the print shop, only to friends of the FWGNA
Project.<p></p><p><b>FWGNA Volume 5</b>, by Dillon, Kohl, Winters, Pyron, Reeves,
Watters, Cummings, Bailey and Whitman <b><span style="color: #783f04;">[1]</span></b>, reports the scientific results of a
freshwater gastropod survey covering all or part of 14 U.S. states, a total
study area of over 200,000 square miles.
Our database of 9,370 records, sampled from approximately 4,250 distinct
sites, was drawn from museums (24%), state natural resource agencies (34%), and
personal collections.</p>
<p class="MsoNormal">We document 80 species and 19 subspecies of freshwater
gastropods in this malacologically rich region.<span style="mso-spacerun: yes;">
</span>For each we provide: </p><p class="MsoNormal"></p><ul style="text-align: left;"><li>A dichotomous key for identification. </li><li>Full-color
figures. </li><li>Range maps at county scale. </li><li>Notes on habitat, ecology, life history
and reproductive biology. </li><li>Systematic and taxonomic updates to modern standards.</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">Three new species of cave-dwelling hydrobioid snails:
<i>Fontigens hershleri</i>, <i>F. benfieldi</i>, and <i>F. davisi</i>, are described in the appendix
<b><span style="color: #783f04;">[2]</span></b>.</p><p class="MsoNormal">Our complete FWGNA database, updating Atlantic drainage
records and combining them with our fresh data from the interior, now comprises
22,044 records documenting 107 species of freshwater gastropods, with 21
subspecies. In Volume 5 we offer a new
continent-scale biogeographic analysis, dividing records into North Atlantic,
South Atlantic, Ohio, and Tennessee/Cumberland subsets. Our analysis suggests that natural selection
has been more important in the evolution of freshwater pulmonate snails than
gene flow restriction, but that gene flow restriction has been more important
in the evolution of freshwater prosobranch snails than natural selection.</p><p class="MsoNormal"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4Q-35QYGCcC0XPfv-D9-cMORg4EPj8s9BUkR6vR71da5hzabPw5d05n-BOgMTNDJ6Hhdwj1PopYvIndqcQflQ_YeaPPbm_k57hklvHY592DgTf0Z00Gc1Hfq9679JGbJBY356uG4m7BUB-kY1K2RG0FCM-jtG3IbKvpa4UCuAfIW2YjypV_g-Id7XccXu/s2559/Vol6-front-cover.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="2559" data-original-width="1700" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj4Q-35QYGCcC0XPfv-D9-cMORg4EPj8s9BUkR6vR71da5hzabPw5d05n-BOgMTNDJ6Hhdwj1PopYvIndqcQflQ_YeaPPbm_k57hklvHY592DgTf0Z00Gc1Hfq9679JGbJBY356uG4m7BUB-kY1K2RG0FCM-jtG3IbKvpa4UCuAfIW2YjypV_g-Id7XccXu/w133-h200/Vol6-front-cover.jpg" width="133" /></a></div>In Volume 1 (2019) we pioneered a new method to rank
freshwater gastropods by incidence categories for the purposes of conservation,
based on the work of K. J. Gaston. Here
in Volume 5 that system is updated to include all 107 species across all
regions, re-assigning incidence ranks as necessary.<p></p><p class="MsoNormal">Our modern understanding of the taxonomy and systematics of
the North American freshwater gastropod fauna is a function of both the natural
history of the vast rivers, lakes and streams through which that diverse fauna
has evolved, and the human history of the biologists who have come behind,
struggling to catalog the biodiversity as it has elaborated before their
eyes. In <b>FWGNA Volume 6 <span style="color: #783f04;">[3]</span></b> we collect
32 essays, originally published on the present blog 2019 – 2023, exploring the
relationship between natural history, human history, and the evolutionary
models we impose today upon the pleurocerid snails of the American interior,
and upon the hydrobioid snails, broadly understood.</p><p class="MsoNormal">Featured topics include intrapopulation gene flow, barriers
to dispersal, character phase disequilibrium, and speciation. Special attention is called to the phenomena
of cryptic phenotypic plasticity and mitochondrial superheterogeneity, both of
which were introduced in Volume 3 of the present series (2019). Along the way we meet Professor Gerard
Troost, who was twice-captured and ransomed by privateers, Captain S. S. Lyon,
who singlehandedly saved the Union command of George W. Morgan in 1862, and Dr.
Isaac Lea, the Nestor of American Naturalists, who drives us nuts. Together these 32 studies comprise an
essential companion to the scientific results of the 14-state survey of the
freshwater gastropod fauna The Ohio, Cumberland, and Tennessee River systems
published in Volume 5.</p><p class="MsoNormal"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiveQv_sCQfcG9Tkyg_NIu2z9b8EC6Revc1iUTPD69vhABGkeTOkxs9HxLRHcy2F1FPgENnAzwdL0C5h4IeDIp9OMnah3Ico5WbHj-OyQ5Ap1zd5JWO2MUSMQVo_VoTg5sGOwU7QpVNYFdBb_PVPEjlCDyMePyJjnWr6aXSSwvOeYaU0zrwIOzdHMTTqWyT/s2555/Vol7-front-cover.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="2555" data-original-width="1691" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiveQv_sCQfcG9Tkyg_NIu2z9b8EC6Revc1iUTPD69vhABGkeTOkxs9HxLRHcy2F1FPgENnAzwdL0C5h4IeDIp9OMnah3Ico5WbHj-OyQ5Ap1zd5JWO2MUSMQVo_VoTg5sGOwU7QpVNYFdBb_PVPEjlCDyMePyJjnWr6aXSSwvOeYaU0zrwIOzdHMTTqWyT/w133-h200/Vol7-front-cover.jpg" width="133" /></a></div>And what is the place of freshwater snails in modern
culture, if any? Does their alleged
rarity and undeniable strangeness elicit conservation concern in small circles
of the environmentally conscious? Might
even smaller circles of professionals in tropical medicine and health worry
about their potential to host parasitic diseases? And aren’t some freshwater snails invasive? Or maybe they’re just cute pets?<p></p><p class="MsoNormal">Collected in <b>FWGNA Volume 7</b> <b><span style="color: #783f04;">[4]</span></b> are 36 essays, originally
published in the genre-defining artistic universe known as the FWGNA Blog,
exploring freshwater gastropod biology in the modern milieu.<span style="mso-spacerun: yes;"> </span>Our focus here is on the larger prosobranchs
– the viviparids and the ampullariid “mystery snails” – as well as on the
familiar pulmonate snails of the hobbyist aquarium and the lab bench.<span style="mso-spacerun: yes;"> </span></p><p class="MsoNormal">Reproductive allocation and the species concept, especially
as applied to asexually-reproducing populations, emerge as primary themes,
together with the omnipresent phenomenon of phenotypic plasticity. And along the way we’ll check in with Gary, a
pet mystery snail, who doesn’t smell so good.
The essays collected here will be an essential companion both to the
Volume 1 results of the FWGNA surveys of Atlantic drainages published in 2019,
and to the results of the Volume 5 Ohio drainage surveys published alongside.</p><p class="MsoNormal" style="text-align: center;"><span style="font-size: medium;"><a href="https://store.bookbaby.com/profile/dillon" target="_blank">Buy Yours Now!</a></span></p><p class="MsoNormal">The retail price of these three indispensable volumes, if
purchased separately, would be $56.00 + $48.89 + $53.79 = $158.68. But we have worked out a special deal with
the print shop for friends of the FWGNA Project. Go directly to my author page on the
printer’s website, link above. Add each
of the three new titles <b><span style="color: #783f04;">[5] </span></b>separately to your cart and proceed to checkout. At the checkout page you will find a box to
enter a “coupon code.” Apply the coupon
code<span style="color: red;"> </span><b><span style="color: red;">FWGNA3</span></b> to each of the three volumes.
This will discount your price to $99.95 for the set. A bargain!</p><p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Dillon, R.T. Jr.,
M. Kohl, R. Winters, M. Pyron, W.K. Reeves, G.T. Watters, K. Cummings, J.
Bailey, & M. Whitman (2023a) <i>Ohio, Cumberland, and Tennessee River
Systems</i>. Freshwater Gastropods of North
America, Volume 5. FWGNA Press,
Charleston, SC. 315 pp.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> Dillon, R.T., Jr., T.E. Malabad, W.D. Orndorff &
H-P. Liu (2023) Three new <i>Fontigens</i> (Caenogastropoda: Fontigentidae) from caves
in the Appalachian Ridge and Valley Province, Virginia. Pp. 283 - 306 <b>in</b>
Dillon, R.T., Jr. et al. The Freshwater Gastropods of North America Volume V:
<i>Ohio, Cumberland, and Tennessee River Systems</i>. FWGNA Press, Charleston. [<a href="https://www.fwgna.org/dillonr/Dillon-Malabad-Orndorff-Liu.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Dillon, R.T., Jr. (2023b) <i>Yankees at The Gap, and Other
Essays</i>. Freshwater Gastropods of North America Volume 6. FWGNA Press, Charleston, SC. 306 pp.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4] </span></b>Dillon, R.T., Jr. (2023c) <i>Collected in Turn One, and Other Essays</i>. Freshwater Gastropods of North America Volume
7. FWGNA Press, Charleston, SC. 345 pp.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5] </span></b>Oh, and the special deal we worked out for Volumes 1 – 4
back in 2019 is still valid. If you
follow the entire procedure outlined above for Volumes 1 – 4 and add the coupon
code <span style="color: red;">FWGNA4</span>, you will receive a discounted price of $99.95 for that set as
well.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-80296925515620136012023-11-08T09:53:00.002-05:002023-11-08T10:04:22.256-05:00Atlantic Drainages Update<p>Our hunger to advance the cause of freshwater gastropod
science is insatiable here at the general headquarters of the FWGNA
Project. I’m always scanning the
literature for the latest research and looking to add new records to the
database, even for those regions we covered and published many years ago, from
which we seem to have long moved on. We
haven’t “moved on” from anywhere. Our
coverage extends over all or part of 17 states, expanding south and west,
active to the present day.</p><p>But it has been ten years – if you can believe it – since we
last updated the five web resources that cover the freshwater gastropod fauna
of U.S. Atlantic drainages: Georgia
(<a href="https://www.fwgna.org/FWGGA/" target="_blank">FWGGA</a>), South Carolina (<a href="https://www.fwgna.org/FWGSC/" target="_blank">FWGSC</a>), North Carolina (<a href="https://www.fwgna.org/FWGNC/" target="_blank">FWGNC</a>), Virginia (<a href="https://www.fwgna.org/FWGVA/" target="_blank">FWGVA</a>) and
the Mid-Atlantic (<a href="https://www.fwgna.org/FWGMA/" target="_blank">FWGMA</a>).</p><p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhFHCrozOMuSW9ztQLlwGm53hfBSrwPhBfGaknKLU2uGDkTXAinHBihhvWiof9KqXnup2rDnlEIVSKSDKWMCreS2VSFuwv2imhu7eeGZ0RhMkukdnKJDHW6_ZWeFa_4WidgpmpSWMg-dAuuv3kUJ-LKBqv2j5HkR-kIlJ6EoAoduDhVJXInpsJ37NAw3UUt/s2627/FWGAD-2023.jpeg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2627" data-original-width="1920" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhFHCrozOMuSW9ztQLlwGm53hfBSrwPhBfGaknKLU2uGDkTXAinHBihhvWiof9KqXnup2rDnlEIVSKSDKWMCreS2VSFuwv2imhu7eeGZ0RhMkukdnKJDHW6_ZWeFa_4WidgpmpSWMg-dAuuv3kUJ-LKBqv2j5HkR-kIlJ6EoAoduDhVJXInpsJ37NAw3UUt/s320/FWGAD-2023.jpeg" width="234" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Fresh 2023 Format</span></td></tr></tbody></table>So a couple months ago we were able to twist the arm of our
good friend Martin Kohl to help us with a fresh set of maps, which is the
biggest piece of the chore. And today we
are pleased to announce that the results of Martin’s considerable GIS skills
are now available for download from the pages of the 72 species and subspecies
of gastropods inhabiting rivers, lakes, ponds and streams of the vast
(ten-state) Atlantic-drainage area.</p><p>The maps newly available for 2023 are built on a database of
12,138 records. That number represents a
4.2% reduction from the 12,674 Atlantic-drainage records upon which we based
our (most recent) Synthesis v3.1 and Biogeography v2.0 back on 12May22. The new total reflects a pruning of our FWGNC
database from 4,425 down to 3,809 records to remove a big batch of
near-duplicate samples, collected by NCWRC teams upstream and downstream from
bridges, for example.</p><p>Other FWGNA Atlantic-drainage databases have been slightly
augmented by routine collecting, however, up from 895 to 960 in Georgia, from
1,938 to 1,989 in South Carolina, from 2,333 to 2,396 in Virginia, and from
3,150 to 3,159 in the Mid-Atlantic states.
Note that the sum of those five figures totals slightly more than 12,138
due to double counting where rivers comprise state lines.</p><p>Our 2013 maps emphasized rivers, streams, and vegetative
cover. Our new 2023 maps have been
significantly reformatted to show the major USGS/EPA Ecoregions, with counties
and cities (very lightly) in the background.
Close comparison of the two examples (above and below) will reveal a
slight reduction in data density for North Carolina, and some fresh data
mapped, especially in Georgia.<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiU7SKJmSKsWUH0GohcV5LdUrT80AFBPa29mNSPwWIuIULnszuOY3b76KhopGmQ49creh44UjvzjNiHmkf6gF6tT_yIDfJxBIhcs7i9uXHeK-7txwMMg5IX7FWJZwLJOFh52tAneRwJPMYjJefvtxlMalfjZWwfVroVX_wgc3EJU0TSJ1aifLv8KGmvIh8b/s2304/FWGAD-2013.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1728" data-original-width="2304" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiU7SKJmSKsWUH0GohcV5LdUrT80AFBPa29mNSPwWIuIULnszuOY3b76KhopGmQ49creh44UjvzjNiHmkf6gF6tT_yIDfJxBIhcs7i9uXHeK-7txwMMg5IX7FWJZwLJOFh52tAneRwJPMYjJefvtxlMalfjZWwfVroVX_wgc3EJU0TSJ1aifLv8KGmvIh8b/s320/FWGAD-2013.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Old 2013 Format</span></td></tr></tbody></table></p><p>The contents of all 128 species pages on the FWGNA site have
also been refreshed in recent months – not just the 72 species and subspecies
of Atlantic drainages. I am always on
the lookout for new research to add to the bibliographies – ecology, life
history, systematics, evolution – anything and everything, really.</p><p>Whenever any of you publish anything new, please send me a
link or a reprint. Indeed, if you happen
to read a new paper with especially interesting or important results on any
aspect of the biology of North American freshwater gastropods, written by
anybody else, I always appreciate a heads-up.</p><p>For many years, my customary sign-off has been, “Keep in
touch.” I mean it, I’m serious!</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-47432619795523948132023-10-06T14:29:00.009-04:002023-10-28T13:10:44.935-04:00Deadly Snails Invading the US!<p>Yesterday evening my wife and I were having supper with family friends when a young lady – very much attuned to social media of diverse
sorts, as so many of the youth these days – mentioned that she had been
“bombarded” with alerts about dangerous snails in North Carolina. This was completely out of the blue. She’s not a biologist – does not follow
technical news feeds – just a regular citizen of the Charleston area in her
mid-20s.</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgIQJdTZlL58NAbCWk_lHa9aB4Otb4dbgs6TTLVgdquWZ2LpXpFXc9whBR4Z790CI1SDnP5i5URQMdTC-yhQPaNn6qX5zU2Pw2ysgcRfHzy3EPRpu4fCyxJ3xdS7S-b16TqgniDUkVbn2AidsgbSVYb1ckrSntg9E-jpteTwtpPJwQR8mWc6zu7yLInS_Cu/s810/Pomacea-NCWRC.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="675" data-original-width="810" height="167" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgIQJdTZlL58NAbCWk_lHa9aB4Otb4dbgs6TTLVgdquWZ2LpXpFXc9whBR4Z790CI1SDnP5i5URQMdTC-yhQPaNn6qX5zU2Pw2ysgcRfHzy3EPRpu4fCyxJ3xdS7S-b16TqgniDUkVbn2AidsgbSVYb1ckrSntg9E-jpteTwtpPJwQR8mWc6zu7yLInS_Cu/w200-h167/Pomacea-NCWRC.jpg" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">NCWRC</span></td></tr></tbody></table>I, very much the opposite, confessed complete ignorance of
the situation. So, our young friend
whipped out her smart phone, deftly touched off three key strokes and a swipe, and there was
the news. Invasive <i>Pomacea</i> of the
<i><a href="https://www.fwgna.org/species/ampullariidae/p_insularum.html" target="_blank">maculata/canaliculata</a></i> sort have been reported in the Lumber River at Lumberton,
NC. But my goodness, the hysteria!<p></p><p>The media frenzy seems to have been kicked off by a
perfectly responsible press release from the North Carolina Wildlife Resources
Commission on Monday 2Oct23 <b><span style="color: #783f04;">[1]</span></b>. Initially
alerted by a concerned citizen, the NCWRC conducted a survey that did indeed
confirm an invasive <i>Pomacea</i> population extending from the I-95 bridge just
above Lumberton <b><span style="color: #783f04;">[2]</span></b> to a boat ramp about 6 km downstream. In measured tones, the press release
cautioned:</p><p></p><blockquote><span style="font-size: x-small;">“Apple Snail grazing habits can damage plants used by many
native aquatic species and they have even been observed feeding on amphibian
eggs. Additionally, Apple Snails can present human health risks. They may carry
rat lungworm, which can cause a potentially fatal disease in humans if the
snails are eaten raw or undercooked.”</span></blockquote><p></p><p>From that relatively innocuous paragraph came the <a href="https://nypost.com/2023/10/04/deadly-apple-snails-found-along-north-carolina-river/" target="_blank">New York Post</a> headline of 4Oct23, “Deadly Apple Snails found along North Carolina River,”
and from <a href="https://www.cbsnews.com/news/invasive-snails-deadly-humans-found-north-carolina/" target="_blank">CBS News</a>, “Invasive snails that can be deadly to humans found in North
Carolina.” But my favourite headline
came from the <a href="https://www.dailymail.co.uk/sciencetech/article-12593631/apple-snails-north-carolina-rat-lungworm.html" target="_blank">UK Daily Mail</a>, <b>“Invasive Snails Deadly to Humans are Invading the
US!” </b>[<a href="https://www.dailymail.co.uk/sciencetech/article-12593631/apple-snails-north-carolina-rat-lungworm.html" target="_blank">html</a>] [<a href="https://www.fwgna.org/downloads/Daily-Mail-Pomacea.pdf" target="_blank">pdf</a>] </p><p>The Lumber River continues into South Carolina to unite with
the PeeDee River about 50 km downstream from Lumberton. Another 80 km downstream by kayak through
impenetrable swamp would bring us to the mouth of the Waccamaw River, from
whence it is but 10 – 15 km back upstream to Socastee, SC, where invasive
<i>Pomacea</i> were first reported in 2008 <b><span style="color: #783f04;">[3]</span></b>.
Whether the North Carolina population represents a new introduction, or
simply a 150 km expansion of the South Carolina population, remains to be
determined.</p><p>We saw a similar wave of concern spread through the Myrtle
Beach area of South Carolina when the snails first arrived here 15 years ago,
although much lower in amplitude and local in extent. The local newspapers here described apple
snails as merely “harmful” or “worrisome,” not “deadly.”</p><p>In retrospect, the NCWRC might have added significantly more
context to their press release. South Carolina researchers have
found no evidence of <i>Angiostrongylus</i> parasitism in samples of <i>Pomacea</i> taken
here in The Palmetto State <b><span style="color: #783f04;">[4]</span></b>. Indeed, the
extensive 2013 survey conducted by Teem and colleagues across Louisiana, Texas,
Mississippi, and Florida yielded only 8 cases of <i>Angiostrongylus</i> parasitism in
296 <i>Pomacea</i> tested, all from the New Orleans area <b><span style="color: #783f04;">[5]</span></b>. And as for cases of actual rat lungworm disease
in humans, the CDC was only able to confirm 12 cases in the continental USA 2011 - 2017, the majority of which were linked to eating raw vegetables, not snails <b><span style="color: #783f04;">[6]</span></b>.</p><p>So when invasive <i>Pomacea</i> arrive in Virginia, here’s a
suggestion for that press release. Bold
the clause, “<b>if the snails are eaten</b>.” And suggest that the readership resist the temptation to pop one in their mouths. Everything will be OK.</p><p><u>Notes</u></p><p><b><span style="color: #783f04;">[1]</span></b> Invasive Apple Snails Now Confirmed in North
Carolina. North Carolina Wildlife
Resources Commission, 2October23. [<a href="https://www.ncwildlife.org/Connect-With-Us/invasive-apple-snails-now-confirmed-in-north-carolina" target="_blank">html</a>] [<a href="https://www.fwgna.org/downloads/NCWRC-Pomacea.pdf" target="_blank">pdf</a>]</p><p><b><span style="color: #783f04;">[2]</span></b> In my blog post of <a href="https://fwgna.blogspot.com/2018/06/invasive-species-updates.html" target="_blank">13June18</a>, I advocated legislation to
build “a big, beautiful wall on the North Carolina line from Cape Hatteras to
Tennessee, 50 feet tall by back-of-the-envelope calculation, Pedro himself
manning the I-95 guardhouse just two mucus trails and one gigantic traffic jam
North of the Border” to intercept just such a <i>Pomacea</i> invasion as North
Carolina is now experiencing here in 2023.
See, I told you so.</p><p><b><span style="color: #783f04;">[3]</span></b> More about <i>Pomacea</i> in South Carolina:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Pomacea spreads to South Carolina [<a href="https://fwgna.blogspot.com/2010/02/pomacea-spreads-to-south-carolina.html" target="_blank">15May08</a>]</li><li>Two dispatches from the Pomacea front [<a href="https://fwgna.blogspot.com/2008/08/two-dispatches-from-pomacea-front.html" target="_blank">14Aug08</a>]</li><li>Pomacea News [<a href="https://fwgna.blogspot.com/2013/07/pomacea-news.html" target="_blank">25July13</a>]</li><li>Invasive species updates [<a href="https://fwgna.blogspot.com/2018/06/invasive-species-updates.html" target="_blank">13June18</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Underwood, E.B., M.J. Walker, T.L. Darden & P.R.
Kingsley-Smith (2019) Frequency of occurrence of the rat lungworm parasite in
the invasive island apple snail in South Carolina, USA. Journal of Aquatic Animal Health 31(2): 168 –
172.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Teem, J.L., Y. Qvarnstrom, H.S. Bishop, A.J. DaSilva, J.
Carter, J. White-Mclean, and T. Smith (2013)
The occurrence of the rat lungworm, <i>Angiostrongylus cantonensis</i>, in
nonindigenous snails in the Gulf of Mexico region of the United States. Hawaii J. Med. Publ. Health 72: 11 – 14.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Liu EW, Schwartz BS, Hysmith ND, et al. (2018) Rat Lungworm
Infection Associated with Central Nervous System Disease — Eight U.S. States,
January 2011–January 2017. Morb Mortal Wkly Rep 67:825–828.<o:p></o:p></p><p class="MsoNormal"><br /></p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com3tag:blogger.com,1999:blog-1925453458905823877.post-27433225099907614642023-09-19T10:55:00.003-04:002023-11-23T20:49:01.916-05:00Is Marstonia olivacea extinct?<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b) Malacological mysteries: Is Marstonia olivacea extinct? Pp 269 – 278 <b>in</b> The Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Questions regarding the habitat and range of the hydrobiid
snail known today as <i><a href="https://www.fwgna.org/species/hydrobiidae/m_ogmor.html" target="_blank">Marstonia olivacea</a></i> have always taken precedence over any
other aspect of its biology. Originally
described in the genus <i>Amnicola</i> by Henry Pilsbry in the February 1895 issue of
The Nautilus <b><span style="color: #783f04;">[1]</span></b>, the name had already appeared in that journal twice
previously – first in March of 1894 <b><span style="color: #783f04;">[2]</span></b>, then again in December <b><span style="color: #783f04;">[3]</span></b>.</p><p>Both anticipatory articles were contributed by Prof. H.E.
Sargent of Woodville, AL, and both focused on habitat. In the March article, “Shell collecting in
Northern Alabama,” Professor Sargent observed:</p><p></p><blockquote><span style="font-size: x-small;">“Huntsville, Alabama, is a somewhat exceptional southern
city in that it has an abundant supply of pure spring water bursting forth from
its very foundations. This spring of
sparkling lime water, beside supplying the city mains, affords a constant
stream several feet in width with several inches in depth go to waste. […] The
upper surfaces of the rocks were found to be covered with a species of <i>Amnicola
</i>which the Editor … proposes the name of <i>Amnicola olivacea</i> Pils.”</span></blockquote><p></p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQ82rNVleKj6HzvjSot_hBTsj7xthpSe5-CqFQuF269CJmNTm9fo_NyX00pjOmMhxUmBs15YNJdzerwS_Jbx2KX0AAM3XsKre0vDou0tHgaTJaMk_eNCGgyuuIK6iDmSNxwdfJwKwnJB951Kq2r5o_WSjjRqKJZITDmaJGViQV4pLIUKSYKJjqDKrF47lU/s400/Big-spring-sign-Huntsville.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="368" data-original-width="400" height="184" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiQ82rNVleKj6HzvjSot_hBTsj7xthpSe5-CqFQuF269CJmNTm9fo_NyX00pjOmMhxUmBs15YNJdzerwS_Jbx2KX0AAM3XsKre0vDou0tHgaTJaMk_eNCGgyuuIK6iDmSNxwdfJwKwnJB951Kq2r5o_WSjjRqKJZITDmaJGViQV4pLIUKSYKJjqDKrF47lU/w200-h184/Big-spring-sign-Huntsville.jpg" width="200" /></a></div><br />And in a little “Notes and News” item tacked onto the end of
the December 1894 issue of The Nautilus, the good professor added,<p></p><p></p><blockquote><span style="font-size: x-small;">“AMNICOLA OLIVACEA PILS. – In April, I visited the original locality
(Huntsville, Ala.) and was surprised to find this species in vast numbers. The stream has a mud bottom which is much
indented with cow tracks. In these the
<i>Amnicola</i> had congregated – not as a layer on the surface, but as a solid mass.
[…] The stream receives some of the city sewerage, so it is probably a good
feeding-ground.”</span></blockquote><p></p><p>Prof. Sargent’s December remark about “sewerage” in
Huntsville’s Big Spring Creek is telling.
We ourselves first visited that unfortunate little body of water in our
essay of [<a href="https://fwgna.blogspot.com/2020/04/huntsville-hunt.html" target="_blank">15Apr20</a>], questing for Isaac Lea’s <i><a href="https://www.fwgna.org/species/pleuroceridae/p_troost_perstriata.html" target="_blank">Melania perstriata</a></i>, and gave it
another nod in last month’s essay [<a href="https://fwgna.blogspot.com/2023/08/the-union-in-tennessee-for-lithoglyphid.html" target="_blank">15Aug23</a>], searching for the illusive
<i><a href="https://www.fwgna.org/species/hydrobiidae/s_parvulus.html" target="_blank">Somatogyrus currierianus</a></i>. The last time
I visited that “marvel to Indian and frontiersmen alike,” I couldn’t even find
a <i>Physa</i>. I have nevertheless marked the
Huntsville Big Spring as <b><span style="color: #2b00fe;">HV</span></b> on the map below.</p><p>But returning to the thread of our story. Henry Pilsbry did not apparently find space
to wedge his formal description of <i>Amnicola olivacea</i> until the fifth article of
the issue he published in February 1895.
And when it appeared it was maddeningly brief and spare, unfigured, and absent any anatomical observations whatsoever <b><span style="color: #783f04;">[4]</span></b>. The two shells that he measured were
unusually large by hydrobiid standards, however, both “Alt 4.2 mm,” and slender
“being of more elongated contour than any other Northern forms except <i><a href="https://www.fwgna.org/species/hydrobiidae/m_lustrica.html" target="_blank">Amnicola lustrica</a></i>.” Those observations plus the
type locality (“Huntsville, Ala., collected by Prof. H. E. Sargent”) were
sufficient to allow subsequent authors to establish the identity of Pilsbry’s
taxon.</p><p>The first among those subsequent authors seems to have been
my hero Calvin Goodrich <span style="color: #783f04;"><b>[5]</b></span>, who wrote in 1944, “This species is somewhat
common in streams and springs in and around Huntsville, Madison County,
Alabama, drained by the Tennessee River.
Specimens taken by Smith in the Coosa, Minnesota Bend, Etowah County,
Alabama <b><span style="color: #783f04;">[6]</span></b>, have been identified as <i>olivacea</i>.”
This strongly implies that Goodrich was aware of populations of
Pilsbry’s<i> A. olivacea</i> at other localities beyond Huntsville’s Big Spring. The four lots of <i>Marstonia olivacea</i> held in
the UMMZ collection today, however, all give locality as either “Huntsville” or
“Huntsville Spring” <b><span style="color: #783f04;">[7]</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaiM2fm66AsTYIhFOdL3h55Zufmn-w5CBmWeVerDTi97LFCEXrtPDpoLpNrrcGW7vJaR2Yr5tsHol-zPLIQKxLbR4vvrpMvj2K8GrrDAr7tKn_K9LzqVpaReNvLwvSbhg9NCHLuujkd1fOpMOLfPfuMcVB6G7D6dGmQS2FEIfwwdFwne9OxVOy7shC5lUg/s742/M_olivacea-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="420" data-original-width="742" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaiM2fm66AsTYIhFOdL3h55Zufmn-w5CBmWeVerDTi97LFCEXrtPDpoLpNrrcGW7vJaR2Yr5tsHol-zPLIQKxLbR4vvrpMvj2K8GrrDAr7tKn_K9LzqVpaReNvLwvSbhg9NCHLuujkd1fOpMOLfPfuMcVB6G7D6dGmQS2FEIfwwdFwne9OxVOy7shC5lUg/w320-h181/M_olivacea-montage.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>M. olivacea</i> <b><span style="color: #783f04;">[12]</span></b>: lectotype, Hershler, UF279638</span></td></tr></tbody></table><p>But Goodrich was a pleurocerid guy, not a hydrobiid
guy. It was Fred Thompson who first
stepped forward to examine Pilsbry’s <i>Amnicola olivacea</i> with a critical eye, in
his landmark monograph of 1977 <b><span style="color: #783f04;">[8]</span></b>. As
my longsuffering readership will remember from last fall [<a href="https://fwgna.blogspot.com/2022/10/the-snhthicacbw-marstonia-5.html" target="_blank">4Oct22</a>], it was
Thompson who first elevated F. C. Baker’s <b><span style="color: #783f04;">[9]</span></b> nomen <i>Marstonia</i> to the level of a
full genus, recognizing as he did eight species in it: Pilsbry’s well-known
<i>lustrica</i>, Pilsbry’s obscure <i>olivacea</i>, and six species of his own.</p><p>Thompson wrote, “Apparently this species (<i>M. olivacea</i>) was
confined to Big Spring Creek in the historic heart of Huntsville.” And he continued, “This snail is probably
extinct. The creek is badly polluted and
has been channelized for most of its course.
No specimens were found by the author during two visits to Big Spring
Creek during 1973.” He went on to
examine the paratype lot (N = 456 specimens!) in the ANSP, valiantly attempting
“to extract and relax dried bodies,” failing.
He selected the shell figured above as a lectotype. And regarding its morphology, Thompson
observed, “If <i>M. olivacea </i>was from a more northern locality, I would be tempted
to consider it a synonym of the highly variable <i>M. lustrica</i>.” He concluded, “This species’ status remains
uncertain.”</p><p>My longsuffering readership will also remember from last
fall [<a href="https://fwgna.blogspot.com/2022/10/the-snhthicacbw-marstonia-5.html" target="_blank">4Oct22</a>] that <i>Marstonia</i> was briefly synonymized under the genus
<i>Pyrgulopsis</i> in 1987 by the dynamic duo of Hershler and Thompson, only to be
resurrected again in 2002 <b><span style="color: #783f04;">[10]</span></b>. In the
interim was published Bob Hershler’s masterful 1994 monograph <b><span style="color: #783f04;">[11]</span></b> treating
Pilsbry’s <i>olivacea </i>as an “Eastern American Species” in the (temporarily very
large) genus <i>Pyrgulopsis</i>.</p><p>My Buddy Bob’s scanning electron micrograph of the shell of
a young <i>“Pyrgulopsis” olivacea</i> <b><span style="color: #783f04;">[12]</span></b> is reproduced middle above. Bob was also apparently able to rehydrate
soft tissues from inside some of Pilsbry’s dried shells, contributing a figure
of the radula and a four-line description of the penial morphology. Hershler left the penis unfigured, alas, and
only compared it to other species in broad outline <b><span style="color: #783f04;">[13]</span></b>. He concluded, briefly, “This snail resembles
widely disjunct <i>P. lustrica</i> in shape of shell and penis, but differs in having
strong spiral lines on the teleoconch.”</p><p>Hershler quoted Thompson’s understanding of the distribution
of <i>P. olivacea</i>, minus any qualification whatsoever, “Known only from type
locality, where it is now extinct.” And
that would seem to be the end of this month’s lesson. Perhaps class will be dismissed early
today? No such luck.</p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimP_Tq5OHBltu9xaBfeVlWG_DGXVDsG8CpBhgxcUpuy645y9xLqFBQ3sy_jJScw8T82Mno9QmOBLf145UqMGAU3t_yRkxJhlV1VL4MXr_MD-ojbiLys1eKUlFxLxv-oBm8FDQK_iwiLXU238XZmstGwD6pUGDFtxt_yUmztKlZ167XHR1B7uhzViLOHBhl/s1052/M-olivacea-map.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="582" data-original-width="1052" height="177" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimP_Tq5OHBltu9xaBfeVlWG_DGXVDsG8CpBhgxcUpuy645y9xLqFBQ3sy_jJScw8T82Mno9QmOBLf145UqMGAU3t_yRkxJhlV1VL4MXr_MD-ojbiLys1eKUlFxLxv-oBm8FDQK_iwiLXU238XZmstGwD6pUGDFtxt_yUmztKlZ167XHR1B7uhzViLOHBhl/s320/M-olivacea-map.jpg" width="320" /></a></div><br />The Florida Museum of Natural History in Gainesville is a
marvelous facility, home to a large and well-curated collection extending well
beyond regional importance. The review I
posted on [<a href="https://fwgna.blogspot.com/2019/05/20-years-of-progress-in-museums.html" target="_blank">22May19</a>] ranked the FLMNH as #5 in the nation by its freshwater
gastropod holdings. I’d like to call it
a beacon on a hill, a guidepost toward which other states and state
universities might sail. But alas, the
tide has turned, and the winds have blown ill for a hundred years. We malacologists of these latter days must
give thanks for the few scattered beacons we have, as we strain to navigate by
their flickering lights.<p></p><p>So it was that on Monday morning, 10Jan22 I found myself
sitting at a metal table in the FLMNH collections, running my fingers through
Fred Thompson’s hydrobioid collections from North Alabama, pondering weak and
weary, over many a quaint and curious lot of freshwater gastropods. And my eye happened to fall on lot UF279638,
collected by FGT from “Madison Co: Huntsville Blue Springs” (site <b><span style="color: #2b00fe;">BA</span></b>) on
17Aug2000 <b><span style="color: #783f04;">[14]</span></b>. That lot of dry shells,
indistinguishable to my eye from common <i>Marstonia lustrica</i>, collected from a
large spring on private property 5 miles East of Huntsville, had been
identified by Fred Thompson himself as <i>Marstonia olivacea</i>. <b><i>Marstonia olivacea</i> is not extinct.</b></p><p>And that was not the last, nor the greatest revelation of
the morning. The FLMNH collection also
held, upon further inspection, a lot UF279620, collected by FGT from Limestone
Creek, about 20 miles west of Huntsville, on 16Aug2000, the previous day. See map point <b><span style="color: #2b00fe;">LC</span></b> above <b><span style="color: #783f04;">[15]</span></b>. That lot, comprising a couple dozen specimens
in 75% ethanol, was curated into the collection as “<i>Pyrgulopsis</i> n. sp.” They were absolutely indistinguishable from
lot UF279638.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMKbn__GMPXi20u1zjM3_kTO39gK1J54DCMKtYlYlob6bsLiUkcUDXpuSilcEAVOKqNBHNx2IyN0lrUD5kTxRuAsl3yzIJE8RLCAeUToAZsBd2eelOsVEnMhJnQB6h1kfiLVYcByOgSYL3d5zDmOsG-pndeDj0ZDYXKDF8OOwU-BuDpZV9VnG9DvtXNyPE/s2560/M_olivacea-wet.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1920" data-original-width="2560" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMKbn__GMPXi20u1zjM3_kTO39gK1J54DCMKtYlYlob6bsLiUkcUDXpuSilcEAVOKqNBHNx2IyN0lrUD5kTxRuAsl3yzIJE8RLCAeUToAZsBd2eelOsVEnMhJnQB6h1kfiLVYcByOgSYL3d5zDmOsG-pndeDj0ZDYXKDF8OOwU-BuDpZV9VnG9DvtXNyPE/s320/M_olivacea-wet.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">UF279620, from Site <b><span style="color: #2b00fe;">LC</span></b></span></td></tr></tbody></table><p>If <i>Marstonia olivacea</i> ranges 5 miles East of Huntsville, and
20 miles West of Huntsville, might it also range 60 miles East of
Huntsville? Begging the indulgence of my
readership, allow me to step back 46 years, and eight paragraphs, and get a
fresh start into this entire story.</p><p>Fred Thompson recognized eight species in his newly elevated
genus <i>Marstonia</i> in 1977: <i>lustrica</i>, <i>olivacea</i>, <i>agarhecta</i> (which he himself had
described in 1969) and five brand new ones.
On page 123 of his monograph, he opined that <i>M. olivacea</i> was endemic to
Huntsville and probably extinct. But two
pages earlier he had newly described <i>Marstonia ogmorhaphe</i> <b><span style="color: #783f04;">[16] </span></b>from Owen
Springs, just over the Tennessee line 60 miles NE of Huntsville (map <b><span style="color: #2b00fe;">OS</span></b>). It was initially “known only from its type
locality,” but a second population of <i>M. ogmorhaphe</i> was subsequently discovered
5 miles west, in the Blue Spring <b><span style="color: #783f04;">[17]</span></b> of Marion County (map <b><span style="color: #2b00fe;">BT</span></b>).</p><p>Thompson made no effort to distinguish his new <i>M. ogmorhaphe</i>
from the older <i>M. olivacea</i>. Quoting him
verbatim from page 120, “<i>Marstonia ogmorhaphe</i> is distinguished from all other
species of <i>Marstonia</i> by (1) its large size (4 – 5 mm), and (2) its large number
of whorls (5.2 – 5.8).” On page 123,
Thompson went on to give the length of the holotype of <i>M. olivacea</i> as 4.35 mm,
and number of whorls as 5.4.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijRAaiUseGQEAe562M8o8n1IbuQzhwfgPjIZTDLChe-fRK1sRY85gwYNKmFD_ndgTC7i-5j-Akjm9fga5QM3Bg8CStI7uAvQRCccsWLPU3zUmJOyM16kHj-Vl3QQ1fKKCSnmb9J8hG2HB6GrX-IN8GwcbODELMTO987uyMVr3hD3hTulcVw4PLEjMYi1b7/s4416/m_olivacea-cressler.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3312" data-original-width="4416" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijRAaiUseGQEAe562M8o8n1IbuQzhwfgPjIZTDLChe-fRK1sRY85gwYNKmFD_ndgTC7i-5j-Akjm9fga5QM3Bg8CStI7uAvQRCccsWLPU3zUmJOyM16kHj-Vl3QQ1fKKCSnmb9J8hG2HB6GrX-IN8GwcbODELMTO987uyMVr3hD3hTulcVw4PLEjMYi1b7/s320/m_olivacea-cressler.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Owen Springs, courtesy of Alan Cressler</span></td></tr></tbody></table><p>Seventeen years later came Bob Hershler’s big <i>Pyrgulopsis</i>
monograph <b><span style="color: #783f04;">[11]</span></b>, and the formal listing of <i>Pyrgulopsis (= Marstonia) ogmorhaphe</i>
as “endangered” by the US Fish and Wildlife Service<b><span style="color: #783f04;"> [18]</span></b>. My buddy Bob’s treatment of this suddenly
noble gastropod, now styled the “Royal Snail,” was brief. Both he and Thompson noted the similarity
between <i>olivacea</i> and <i>lustrica</i>, and both he and Thompson noted the similarity
between <i>ogmorhaphe</i> and <i>lustrica</i>, but neither he nor Thompson thought to compare
<i>olivacea</i> to <i>ogmorhaphe</i>.</p><p>So, in summary. My
biological intuition suggests to me that <b><i>Marstonia ogmorhaphe</i> (Thompson 1977)
is a junior synonym of <i>Marstonia olivacea </i>(Pilsbry 1895)</b>. The dispersal capabilities of freshwater
gastropods are much greater, and their specific ranges much wider than they are
commonly given credit for, even among professionals. The (effectively indistinguishable) <i>Marstonia
lustrica</i> ranges across 12 states and 3 Canadian provinces and must have spread
across most of this vast territory since the Pleistocene <b><span style="color: #783f04;">[19]</span></b>. I cannot see why populations of a second very
similar species, best identified as <i>Marstonia olivacea</i>, could not spread 60
miles from North Alabama to East Tennessee.
And I cannot find a single speck of evidence suggesting that any
reproductive isolation may have evolved subsequently.</p><p><u>Notes</u></p><p><b><span style="color: #783f04;">[1]</span></b> Pilsbry, H.A. (1895) New American fresh-water
mollusks. Nautilus 8: 114 – 116.</p><p><b><span style="color: #783f04;">[2]</span></b> Sargent, H.E. (1894) Shell collecting in Northern
Alabama. Nautilus 7: 121 – 122.</p><p><b><span style="color: #783f04;">[3]</span></b> Sargent, H.E. (1894) <i>Amnicola olivacea</i> Pils. Nautilus 8: 95 – 96.</p><p><b><span style="color: #783f04;">[4]</span></b> My faithful readership will be familiar with the
eccentricities of the character of The Ancient Emperor, Dr. Henry A.
Pilsbry. In his capacities as Curator of
Mollusks at The Academy of Natural Sciences of Philadelphia and Editor of The
Nautilus, he cast a giant shadow across the face of American malacology for 70
years. You are also aware that Pilsbry
was simultaneously fastidious and sloppy, capable of precise, detailed, and
critical observations of parrot feathers in a pirate attack. For more, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Emperor Speaks [<a href="https://fwgna.blogspot.com/2020/12/the-emperor-speaks.html" target="_blank">5Dec20</a>]</li><li>The Emperor, the Non-child, and the Not-short-duct [<a href="https://fwgna.blogspot.com/2021/02/the-emperor-non-child-and-not-short-duct.html" target="_blank">9Feb21</a>]</li><li>Dr. Henry A. Pilsbry was a Jackass [<a href="https://fwgna.blogspot.com/2021/01/dr-henry-pilsbry-was-jackass.html" target="_blank">26Jan21</a>].</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Goodrich, C. (1944) Certain operculates of the Coosa
River. Nautilus 58: 1 – 10.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> The “specimens taken by Smith in the Coosa” were
described as <i>Marstonia hershleri</i> by</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Thompson, F. G. (1995) A new freshwater snail from the Coosa
River, Alabama (Gastropoda: Prosobranchia: Hydrobiidae). Proc. Biol. Soc. Washington 108: 502 – 507.</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> All of these lots are undated, alas. They are catalogue numbers 120720 of H.E.
Sargent, 143685 of H.H. Smith, 237147 of P.L. Marsh, and 1516 of an unknown
collector.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8] </span></b>Thompson, F.G. (1977) The hydrobiid snail genus
<i>Marstonia</i>. Bulletin of the Florida State
Museum 21(3):113-158.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9] </span></b>Baker, F. C. (1926) Nomenclatural notes on American
fresh water Mollusca. Transactions of the Wisconsin Academy of Sciences, Arts,
and Letters 22:193-205.</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Thompson, F. G. & R. Hershler (2002) Two genera of North American freshwater
snails: <i>Marstonia </i>Baker, 1926, resurrected to generic status, and <i>Floridobia</i>,
new genus (Prosobranchia: Hydrobiidae: Nymphophilinae). The Veliger 45: 269 - 271.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11] </span></b>Hershler, R. (1994)
A review of the North American freshwater snail genus <i>Pyrgulopsis</i>
(Hydrobiidae). Smithsonian Contributions
to Zoology 554: 1 - 115.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> The standard lengths of these three figured shells are
4.3 mm for Thompson’s <b><span style="color: #783f04;">[8] </span></b>lectotype, 4.5 mm for my selection from lot UF279638,
and just 3.4 mm for Hershler’s <b><span style="color: #783f04;">[11] </span></b>youngish specimen. My Buddy Bob had a longtime romance with
scanning electron microscopy, and tended to select smaller shells for his
figures, which are easier.</p><p class="MsoNormal"><b><span style="color: #783f04;">[13] </span></b>In fairness to Bob Hershler, the morphology of dried
and rehydrated soft tissues cannot be compared to anything other than other
dried and rehydrated soft tissues. I
would have loved to see a comparison of the penial morphology of <i>M. olivacea,
M. lustrica</i> and <i>M. ogmorhaphe</i>, but to do so Bob would have had to desiccate a
bunch of fresh <i>lustrica</i> or <i>ogmorhaphe</i> to brittle dryness first.</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> There is an error in the lat/long coordinates for
UF279638 as entered into the FLMNH database, which may have contributed to the
obscurity of this record. The correct
lat/long coordinates for the Blue Spring of Madison County, Alabama, are
34.7080, -86.5123. They are not
“31.66361, -85.50667.” Those are the
coordinates of the Blue Springs of Barbour County, AL.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> This spot is way downstream near the mouth of Limestone
Creek, underneath the I-565 spur, at 34.6317, -86.8667.</p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> Thompson spelled his new species “<i>ogmorphaphe</i>” at the
heading of his description and
“<i>ogmorhapha</i>” in his table of contents, but “<i>ogmorhaphe</i>” enough times otherwise
to make the one-pee-final-e spelling stick.</p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> To be very
clear. The Blue Spring of Marion County,
Tennessee (35.0816, -85.6325) is different from both the Blue Spring of Madison
County, Alabama (34.7080, -86.5123) and the Blue Springs of Barbour County,
Alabama (31.6636, -85.5067).</p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> U.S. Fish and Wildlife Service (1994) Endangered and
threatened wildlife and plants; Determination of endangered status for the
Royal Snail and Anthony’s Riversnail.
Federal Register 59: 17994 – 17998.
[FR-1994-04-15]</p><p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> The hypothesis I am offering here is now fair game for
testing with a gene tree. But if you are
a bright young graduate student looking for thesis ideas, please first read
Essay the paper by Tom Coote <b><span style="color: #783f04;">[20]</span></b>. Then read this essay, and the essays linked
from it:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Mitochondrial heterogeneity in Marstonia lustrica [<a href="https://fwgna.blogspot.com/2020/08/mitochondrial-heterogeneity-in.html" target="_blank">3Aug20</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[20]</span></b> Coote, T. W. (2019)
A phylogeny of Marstonia lustrica (Pilsbry 1890) (Gastropoda:
Hydrobiidae) across its range.
Northeastern Naturalist 26: 672 – 683.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-42738773873742300252023-08-15T11:30:00.004-04:002023-11-23T20:57:46.860-05:00The Union in Tennessee! For lithoglyphid hydrobioids, that is.<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b) The Union in Tennessee! For lithoglyphid hydrobioids, that is. Pp 289 – 298<b> in</b> The Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>In last month’s episode [<a href="https://fwgna.blogspot.com/2023/07/somatogyrus-and-yankees-in-north-alabama.html" target="_blank">11July23</a>], we marched south from
Tennessee into Alabama with Gen. Ormsby Mitchel, the First Michigan Engineers
and Mechanics Regiment, and Dr. W. H. DeCamp.
Capturing Huntsville on the morning of April 10, 1862, Mitchel’s forces
moved rapidly both East and West to secure the vital Memphis & Charleston
Railroad, by the end of the summer controlling 100 miles of riverbank on the
north side of the Tennessee River. And
somewhere in the vicinity of Huntsville, sometime during that long and exciting
summer of 1862, Dr. William Henry DeCamp, Surgeon US Army, collected a small
sample of small lithoglyphid hydrobioids that turned out to be the first
<i>Somatogyrus</i> described from the drainage of The Tennessee River, <i><a href="https://www.fwgna.org/species/hydrobiidae/s_parvulus.html" target="_blank">Somatogyrus currierianus</a></i> (Lea 1863) <b><span style="color: #783f04;">[1, 2]</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6k9gNsu1-4VVXxDGUmoZteZB1fi1Bud0wgDZpHJ16w4boryfs1BEiBhglll2PlMhu0S4idH1cB-i5qSZC1QvpmTfBQXrUnwcWxsD-_8KS1vape5SfIlORTd3AK13DscpUbal7VV8pwsH9WK8LG20tT1qGcTJxBrG6raL0f_YzfuQYsl3_MXANqSPRLbB1/s2965/Alabama-campaign.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1637" data-original-width="2965" height="221" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6k9gNsu1-4VVXxDGUmoZteZB1fi1Bud0wgDZpHJ16w4boryfs1BEiBhglll2PlMhu0S4idH1cB-i5qSZC1QvpmTfBQXrUnwcWxsD-_8KS1vape5SfIlORTd3AK13DscpUbal7VV8pwsH9WK8LG20tT1qGcTJxBrG6raL0f_YzfuQYsl3_MXANqSPRLbB1/w400-h221/Alabama-campaign.jpg" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">North Alabama campaign <b><span style="color: #783f04;">[3]</span></b></span></td></tr></tbody></table><p>Last month we also
reviewed what is known about the distribution of <i>Somatogyrus </i>elsewhere
throughout the Tennessee drainage, both historic and modern. East Tennessee populations have typically
been identified with Tryon’s (1865) nomina <i>S. parvulus</i> and <i>S. aureus</i> <b><span style="color: #783f04;">[4]</span></b>, the
former name prevailing in the tributary rivers above Knoxville, the latter
further downstream in Knoxville and vicinity.
The Hiwassee hosts a well-documented population of <i>Somatogyrus</i>
apparently trans-Appalachian in origin, and the little snails also pop up
occasionally in TN-DEC macrobenthic samples collected from Chickamauga Creek
near Chattanooga as well.</p><p>Middle Tennessee populations are less well-known, and if
identified at all, are usually assigned the name<i> Somatogyrus depressa</i>, which
Tryon (1862) used to describe populations in the Mississippi River at
Davenport, Iowa <b><span style="color: #783f04;">[5]</span></b>. These include a
large population inhabiting the Duck River and a small population in the
Harpeth River, a tributary of The Cumberland west of Nashville <b><span style="color: #783f04;">[6]</span></b>.</p><p>Between the East Tennessee populations identified as <i>S. parvulus/aureus</i> and the Middle Tennessee
populations identified as <i>S. depressa</i> are Dr. W. H. DeCamp’s old stomping
grounds in North Alabama. And last month
we concluded that the key to understanding the entire, far-flung <i>Somatogyrus</i>
fauna of the Tennessee River system is to understand that little sample of
little snails Dr. DeCamp collected at “Huntsville” in 1862, sent to Isaac Lea
and described as currieriana the following year <b><span style="color: #783f04;">[1]</span></b>. Can Dr. DeCamp’s type population be found
again?</p><p>That question weighed heavily on my mind as I tipped my hat
to the Missus and boarded a westbound train for Alabama in August of 2021
<b><span style="color: #783f04;">[7]</span></b>. The Huntsville <i>Somatogyrus</i> problem
seemed closely analogous to that with which I had wrestled in the spring of
2020, searching for the type population of <i>Melania perstriata</i>, also described
by Isaac Lea from Huntsville but in 1853, before the war [<a href="https://fwgna.blogspot.com/2020/04/huntsville-hunt.html" target="_blank">15Apr20</a>]. The field notebook under my arm bulged with
many water-stained pages of observations about the malacologically rich area
toward which the Memphis & Charleston Railroad was bearing me that morning.</p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK_kb80SvwCLT5ysgGHZzVYYJxh0iJpaRx10YYGPM9XxUi5mIhA1YgCrYbdaZBowYR1l7X7icJliOR5OwaVrtpRZ4XM3WLy2JDCHP2Qu0U3odHpCWM92DYif9tWxKMPYTMc7xnRPWpehvupM8OYs15nojp15Kt1yywUMe6MDwei_pU8j_Y55xj_ut4KVD0/s4258/Alabama-mules.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="3075" data-original-width="4258" height="144" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK_kb80SvwCLT5ysgGHZzVYYJxh0iJpaRx10YYGPM9XxUi5mIhA1YgCrYbdaZBowYR1l7X7icJliOR5OwaVrtpRZ4XM3WLy2JDCHP2Qu0U3odHpCWM92DYif9tWxKMPYTMc7xnRPWpehvupM8OYs15nojp15Kt1yywUMe6MDwei_pU8j_Y55xj_ut4KVD0/w200-h144/Alabama-mules.jpg" width="200" /></a></div>The city of Huntsville, I knew, had built up around a lovely,
high-volume spring that was almost certainly the type locality of <i><a href="https://www.fwgna.org/species/pleuroceridae/p_troost_perstriata.html" target="_blank">Melania perstriata</a></i>, and which was quite likely the type locality of <i>S. currierianus </i>as
well. But I was also aware that in
modern times the spring and its run have been channeled in concrete bulkheads
through a formal midtown park and rendered essentially devoid of
macrobenthos. I didn’t see any
<i>Somatogyrus</i> there in 2020, when I wasn’t seeing any <i>Pleurocera (“Melania”)
perstriata</i>.<p></p><p>What to do? It seemed
to me that my best option would be to draw a series of concentric circles on my
map around the Big Spring of Huntsville and try to find the <i>Somatogyrus</i>
population next-closest. So, upon
arrival at the Huntsville Depot the next morning, I brushed the cinders from my
frock coat, hired a mule-drawn hack at the livery, and set off down the
Cottonville Pike for the Flint River about 10 miles distant. This, I knew from experience, was the first
body of water my mules would kick into substantial enough to host a population
of <i>Somatogyrus</i>, travelling east. And
soon a second challenge, beyond the 150 years of landscape evolution boggling
my eyes as we clip-clopped by the Starbucks, presented itself.</p><p>The Flint River
<i>Somatogyrus</i> population is weird looking.
I figured a typical specimen in the Cherrytree montage I published in my
[<a href="https://fwgna.blogspot.com/2022/11/the-snhthicacbw-marstonia-6-pachyta.html" target="_blank">3Nov22</a>] essay on <i>Marstonia pachyta</i> and figured a life-sized image of that same
specimen again last month [<a href="https://fwgna.blogspot.com/2023/07/somatogyrus-and-yankees-in-north-alabama.html" target="_blank">11July23</a>], and I’m going to show you a third time
this month, marked <b>Fl</b> in the figure below.
The Flint River population seems to reach adulthood at an exceptionally
small size, no more than maybe 2-3 mm shell length. The shells they bear are also unusually light
and – here’s the big shocker – typically show at least a little bit of
umbilicus. That’s right. Flint River <i>Somatogyrus</i> look like <i>Clappia</i>.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjV2ztHLLeCppOrVvRyMsJxcAuIuBQr3GQCfn5UYc4EwdIBohAs1g1F6TTt3JwNULKeQCpdpEFK6Mue4vKQ9Zk8lsYd9DQ2ZA49ewtfLkDGJA0hRybO328Da_1-WyAq1g-llMz4q047hRbUyzn6cV-VTCrJ2l3SnH1L9MSmMd2FTn-h82yhvkvS5Y6r4uD7/s2693/somatogyrus-montage-big.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2028" data-original-width="2693" height="241" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjV2ztHLLeCppOrVvRyMsJxcAuIuBQr3GQCfn5UYc4EwdIBohAs1g1F6TTt3JwNULKeQCpdpEFK6Mue4vKQ9Zk8lsYd9DQ2ZA49ewtfLkDGJA0hRybO328Da_1-WyAq1g-llMz4q047hRbUyzn6cV-VTCrJ2l3SnH1L9MSmMd2FTn-h82yhvkvS5Y6r4uD7/s320/somatogyrus-montage-big.jpg" width="320" /></a></div><p>I also figured the
type of Lea’s <i>S. currierianus</i> last month, and I apologize about the quality of
that image; the original picture was only about 5 mm in the monograph. But Lea’s figure showed a much more robustly
shelled snail, no umbilicus in evidence, as is typical for the genus. Standing ankle-deep in the Flint River in the
summer of 2021, holding the reins of a brace of wet mules in my left hand, I
simply could not bring myself to designate the weird-looking little <i>Somatogyrus</i>
crawling around at the bottom of the sawed-off trashcan I was holding in my
right, as topotypic <i>currierianus</i>.</p><p>So, I re-mounted my asinine conveyance, and with a light
touch of the whip continued eastward another 10 dusty miles or so beyond the
Flint, to the sparkling waters of the Paint Rock River. And there I found a somewhat larger-bodied
and heavier-shelled population of <i>Somatogyrus</i>, a typical specimen from which is
labeled <b>PR</b> above. The Paint Rock
population bears shells that are not umbilicate, and look fairly typical for
the genus, and I thought at the time, might suit as modern topotypes. Storing a sample in my watch pocket, I turned
my wagon back into the setting sun, and returned to Huntsville for the night.</p><p>The next morning, I bought a fresh ticket at the station and
boarded a westbound for Decatur and Tuscumbia.
And I resolved, as I did, to jump off at the first trestle<b><span style="color: #783f04;"> [8]</span></b>, crossing
the Limestone Creek about 15 miles west of the city. She was making 30 miles an hour as we
approached the bridge, but the drop was no more than 12 -15 feet, so I landed
with the loss of no more than my hat, and vision in my left eye.</p><p>The shells borne by the <i>Somatogyrus</i> I plucked from Limestone
Creek looked fairly typical, at least in the downstream precincts of
Mooresville, at the railroad crossing.
See figure <b>Lid</b> above. But as I
made my way upstream, a new and intriguing phenomenon unfolded before my
eyes. The shells of the Limestone Creek
<i>Somatogyrus</i> population began to open an umbilicus. The photo below compares a shell collected
downstream, 1 mile NE of Mooresville (<b>Lid</b>), to a shell collected about 12 miles
upstream, at Capshaw (<b>Liu</b>). Although the
former is quite typical for <i>Somatogyrus</i> populations throughout the Tennessee
drainage, the latter would conventionally be identified as <i>Clappia</i>.</p><p>And then it dawned upon me that I had seen this same
phenomenon in the Powell River ten years previous – a <i>Clappia</i> population
upstream blending into a <i>Somatogyrus</i> population downstream <b><span style="color: #783f04;">[9]</span></b>. Both upstream populations seem to reach
maturity at a smaller size, bear lighter shells, and prefer a substrate of
woody debris on the margins. The
downstream populations are larger, more robustly shelled, and inhabit rocks
midstream. The parallel nature of this
phenomenon, as it apparently manifests itself in both East Tennessee and North
Alabama, suggested to me cryptic phenotypic plasticity of a high and aggravated
nature.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyHD4KKEQiN0ehtNXgBHk4dw50Pxoc8yUy749whWvBL__v7PO0Tr7bOKdhWPX2ZKuPd-Xch4BjGI_zfi-w0wRwe8R-ZBe7zv1URNHnWRh-Nf-t24bGk9egQBmwQLwxxM3NQYKL0ubfe2nX0UF0oX20gQADzzqQVjJW9d9IAMam1VGEfXWqiWjMcT4FO1me/s1678/Somatogyrus28-variable-umbilicus-fix.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="944" data-original-width="1678" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyHD4KKEQiN0ehtNXgBHk4dw50Pxoc8yUy749whWvBL__v7PO0Tr7bOKdhWPX2ZKuPd-Xch4BjGI_zfi-w0wRwe8R-ZBe7zv1URNHnWRh-Nf-t24bGk9egQBmwQLwxxM3NQYKL0ubfe2nX0UF0oX20gQADzzqQVjJW9d9IAMam1VGEfXWqiWjMcT4FO1me/s320/Somatogyrus28-variable-umbilicus-fix.jpg" width="320" /></a></div><p>All these thoughts
tumbled through my mind as I walked the dusty road west toward Piney Creek, no
more than a mile beyond Mooresville. And
what I found in Piney Creek reminded me very much of what I had seen in the
Flint River on the previous day. The
<i>Somatogyrus</i> population of Piney Creek was exceptionally small-bodied, lightly
shelled, and umbilicate, animals reaching adulthood not much more than 2 mm
shell length, as depicted in Figure <b>Pi</b> above.</p><p>That evening I camped under the Decatur bridge, cooked a cup
of chicory coffee in a tin can, and watched the Tennessee River flow by. Actually, the river didn’t flow any more than
I did. Although this stretch of river
would have been wild and free in 1862, the TVA closed Wheeler Dam about 30
miles downstream in 1936, backing the Tennessee River up almost 60 miles to
Huntsville. And all that met my eye that
evening at the Decatur Bridge was slackwater swamp.</p><p>How many molluscan lives were lost as those flat, scummy
waters inundated the historic Muscle Shoals between Florence and Decatur, I
wondered to myself, as the sun set. How
many millions of unionid mussels, how many billions of pleurocerid snails? Throughout the nineteenth century and into
the twentieth, scores of <i>Melania, Anculosa, Leptoxis, Pleurocera, Trypanostoma,
Goniobasis, Lithasia, Angitrema, Strephobasis</i>, and <i>Eurycaelon</i> were described
and re-described from the rivers and streams around Muscle Shoals <b><span style="color: #783f04;">[10]</span></b>. The pleurocerid populations inhabiting the
roiling waters of that mighty river, bearing heavier, more robust shells, were
typically assigned Latin nomina different from more lightly shelled populations
inhabiting the gentler tributaries.</p><p>The <i><a href="https://www.fwgna.org/species/pleuroceridae/p_canaliculata.html" target="_blank">Pleurocera canaliculata</a></i> population inhabiting the main
Tennessee River here at Decatur, I knew, extends up nearby Limestone Creek,
where they were described as <i><a href="https://www.fwgna.org/species/pleuroceridae/p_pyrenellum.html" target="_blank">Melania pyrenella</a></i> by Conrad in 1834. Historic
nomina such as Conrad’s <i>pyrenella</i>, although now relegated to synonymy <b><span style="color: #783f04;">[11]</span></b>,
nevertheless have demonstrable utility to describe morphological forms not
apparently correlated with reproductive isolation, possibly ecophenotypic in
origin. We have suggested that such
nomina, especially those around which some published literature has
subsequently developed, be preserved at the subspecific level by virtue of
their indexing function.</p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSNATHbV7YrsYsebZtNgn6OEccY4Hx63yzPMzYoDR0M9R3lwpJ4dP2AwiChCoJZ_Li4uQPuDeE-t5muolEpxV1MUQJnTRb-9TwpDgRaCphwAzLdiRa3oK7_QpmBicfpSN1uxmTO2Ohs9v0sVeiY1BKewYbEyh_t2cukYEW3IVybixgv9YVmIK_Jst2l7Ww/s2204/bivouac-at-Decatur.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="1708" data-original-width="2204" height="155" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSNATHbV7YrsYsebZtNgn6OEccY4Hx63yzPMzYoDR0M9R3lwpJ4dP2AwiChCoJZ_Li4uQPuDeE-t5muolEpxV1MUQJnTRb-9TwpDgRaCphwAzLdiRa3oK7_QpmBicfpSN1uxmTO2Ohs9v0sVeiY1BKewYbEyh_t2cukYEW3IVybixgv9YVmIK_Jst2l7Ww/w200-h155/bivouac-at-Decatur.jpg" width="200" /></a></div>Similarly. In 1906
Bryant Walker described seven species of <i>Somatogyrus</i> from the Muscle Shoals
area, all of which bore robust shells, apparently adapted to large rivers with
strong current <b><span style="color: #783f04;">[12]</span></b>. Figure <b>Sh</b> above
shows a typical specimen of Walker’s <i>S. tennesseensis </i> from the Florida State Museum (cat. 83116),
collected at “Shoals Creek near mouth with Tennessee River” date unknown. That big-river shell morphology seems to
match the image of Lea’s <i>currierianus</i> (see last month) better than any of the
populations inhabiting the smaller tributary waters today. But alas, the <i>Somatogyrus </i>of Muscle Shoals
were buried under the slackwater with the unionids and the pleurocerids in
1936. Gone With The Swamp.<p></p><p>Then by analogy with the better studied pleurocerids, we
suggest that <b>the following nomina are junior synonyms of <i>Somatogyrus
currierianus</i> (Lea 1863):</b> <i>aureus </i>Tryon
1865, <i>excavatus</i> Walker 1906, <i>humerosus</i> Walker 1906, <i>parvulus</i> Tryon 1865,
<i>quadratus</i> Walker 1906, <i>sargenti</i> Pilsbry 1895, <i>strengi</i> Pilsbry & Walker
1906, <i>substriatus</i> Walker 1906, and <i>tennesseensis </i>Walker 1906 <b><span style="color: #783f04;">[4, 12, 14]</span></b>.</p><p>And extending the analogy further. The evidence reviewed above suggests that the
populations described by Bryant Walker in 1904 as <i><a href="https://www.fwgna.org/species/hydrobiidae/c_umbilicata.html" target="_blank">Somatogyrus umbilicata</a></i> <b><span style="color: #783f04;">[15]</span></b>,
separated by him into a new genus <i>Clappia</i> in 1909 <b><span style="color: #783f04;">[16]</span></b>, are lightly shelled
upstream variants of <i>Somatogyrus currierianus</i>.
We therefore propose that <b>Walker’s nomen <i>umbilicata</i> be lowered to
subspecific status under Lea’s S. <i>currierianus</i>.</b></p><p class="MsoNormal">And in conclusion, we take this opportunity to remind our
readership once again that the FWGNA has adopted the definition of the word
“subspecies” standard since the Modern Synthesis, “populations of the same
species in different geographic locations, with one or more distinguishing
traits” <b><span style="color: #783f04;">[17]</span></b>. Although there certainly
may be some heritable basis for the umbilicus demonstrated by the shells of
some small river Somatogyrus populations, and indeed for all the remarkable
shell variety of all the remarkable freshwater malacofauna of North Alabama,
ecophenotypic origins are at least equally likely.</p><p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Lea, I (1863) Descriptions of fourteen new species of
Melanidae and one <i>Paludina</i>. Proceedings
of the Academy of Natural Sciences of Philadelphia 4: 154 – 156.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> Lea, I (1866) New
Unionidae, Melanidae, etc., chiefly of the United States. Journal of the Academy of Natural Sciences of
Philadelphia Series 2, 6: 113 – 187.</p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> This is a small detail from a map of Alabama and
Mississippi published by the United States Coast Survey in 1865. Retrieved from the Library of Congress here: <a href="https://www.loc.gov/resource/g3980.cw0259500/">https://www.loc.gov/resource/g3980.cw0259500/</a></p><p class="MsoNormal">I added the colored marks and notes.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4] </span></b>Tryon, G. W. Jr. (1865)
Descriptions of new species of <i>Amnicola, Pomatiopsis, Somatogyrus,
Gabbia, Hydrobia</i> and <i>Rissoa</i>. American
Journal of Conchology 1: 219-222, pl 22, figs 5-13.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Tryon, G. W. (1862)
Notes on American fresh water shells, with descriptions of two new
species. Proceedings of the Academy of
Natural Sciences of Philadelphia 14: 451 – 452. I really think that <i>Somatogyrus</i> populations of the main Mississippi River are today best identified as<i> <a href="https://www.fwgna.org/species/hydrobiidae/s_integra.html" target="_blank">Somatogyrus integra</a></i> (Say 1829).</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Here’s a download of all 2,152 the Somatogyrus
occurrences in the GBIF, as of 17Oct22: GBIF.org (17 October 2022) GBIF Occurrence Download
<a href="https://doi.org/10.15468/dl.nv3tjh">https://doi.org/10.15468/dl.nv3tjh</a></p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> No, I drove I-20 to I-75 like everybody else these days
and spent two hours in the Atlanta traffic.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Actually, a westbound train from Huntsville will cross
Indian Ck, Bradley Ck, and Beaverdam Ck before arriving at Limestone Ck. None of these smaller streams seems to host a
<i>Somatogyrus</i> population today.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> For a review of Bryant Walker’s contributions to our
understanding of the hydrobioid genera <i>Somatogyrus</i> and <i>Clappia</i>, together with
my own personal observations from East Tennessee on these enigmatic taxa, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Bryant Walker’s Sense of Fairness [<a href="https://fwgna.blogspot.com/2012/11/bryant-walkers-sense-of-fairness.html" target="_blank">5Nov12</a>]</li><li>On getting Clappia in Tennessee [<a href="https://fwgna.blogspot.com/2012/12/on-getting-clappia-in-tennessee.html" target="_blank">3Dec12</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> The actual count of pleurocerid species inhabiting the
waters of North Alabama today totals ten: <i>Leptoxis praerosa, L. crassa,
Lithasia armigera, L. verrucosa, Pleurocera canaliculata</i> (2ssp), <i>P.
clavaeformis</i> (2 ssp.), <i>P. laqueata, P. nassula, P. simplex, P. troostiana</i> (3
ssp).</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Dillon, R. T., S. J. Jacquemin & M. Pyron
(2013) Cryptic phenotypic plasticity in
populations of the freshwater prosobranch snail, <i>Pleurocera canaliculata</i>. Hydrobiologia 709: 117-127. [<a href="https://www.fwgna.org/dillonr/Dillon-Jacquemin-Pyron.pdf" target="_blank">PDF</a>]
For a discussion of these important results, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Pleurocera acuta is Pleurocera canaliculata [<a href="https://fwgna.blogspot.com/2013/06/pleurocera-acuta-is-pleurocera.html" target="_blank">3June13</a>]</li><li>Pleurocera canaliculata and the process of scientific
discovery [<a href="https://fwgna.blogspot.com/2013/06/pleurocera-canaliculata-and-process-of.html" target="_blank">18June13</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> Walker. B. (1906)
New and little known species of Amnicolidae. Nautilus 19: 97-100, 114-117. In this paper Walker (solo) described six
<i>Somatogyrus </i>from Shoal Creek and the main Tennessee River around Florence,
Alabama: <i>substriatus, humerosus, quadratus, excavatus, tennesseenis</i>, and
<i>biangulatus</i> <b><span style="color: #783f04;">[13]</span></b>. He also described
<i>strengi</i> from the same area, which he credited to “Pilsbry & Walker.”</p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> I think that the populations Walker described as
<i>Somatogyrus biangulatus</i> in 1906 may indeed have been biologically distinct, and
now extinct.</p><p class="MsoNormal"><b><span style="color: #783f04;">[14] </span></b>Pilsbry, H.A. (1895) New forms of American shells. Nautilus 8(9): 102.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> Walker, B. (1904)
New species of <i>Somatogyrus</i>. Nautilus 17: 133 - 142.</p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> Walker, B. (1909)
New Amnicolidae from Alabama. Nautilus 22: 85 - 90.</p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> For an elaboration of the concept, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>What is a subspecies?<span style="mso-spacerun: yes;">
</span>[<a href="https://fwgna.blogspot.com/2014/02/what-is-subspecies.html" target="_blank">4Feb14</a>]</li><li>What subspecies are not. [<a href="https://fwgna.blogspot.com/2014/03/what-subspecies-are-not.html" target="_blank">5Mar14</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-69385065775963482772023-07-11T09:13:00.011-04:002023-11-23T20:53:17.920-05:00Somatogyrus and Yankees in North Alabama<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b) Somatogyrus and Yankees in North Alabama. Pp 279 – 288 <b>in</b> The Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Early in the morning of April 10, 1862, eight thousand
Federal troops under the command of Gen. Ormsby Mitchel captured the sleeping
town of Huntsville, Alabama, without firing a shot <b><span style="color: #783f04;">[1]</span></b>. Knowing that both of the main armies were
licking their wounds from the Battle of Shiloh about 120 miles west on the banks
of the Tennessee three days earlier, Mitchel seized the opportunity for a
lightning strike south from Shelbyville.
By the end of April, he controlled 80 miles of the Memphis &
Charleston Railroad from Bridgeport to Decatur, writing to Secretary of the
Army Edwin Stanton, “All of Alabama north of the Tennessee River floats no flag
but that of the Union.” Mitchel’s
Division held North Alabama for four months, withdrawing in reaction to Braxton
Bragg’s thrust north from Chattanooga in August <b><span style="color: #783f04;">[2]</span></b>. By September they were home on the banks of
the Ohio in Louisville.</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5v2t3NDRwWGXcTq70_Tez7vuEd5i5xTsU_m5D5xKPxOMlrMoaY-sopn_LwXSmO6597QOtGNb8zsRI-XlUJJKuRntAOs8hwn3kqBNscEcOPWwBbAy7noh20tWcFasFypPItcwztS08Am6puRil0276f-yn45lcexvMMTi9RQLriIgmX5jO0goGXcvWqzwT/s458/DeCamp.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="266" data-original-width="458" height="186" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5v2t3NDRwWGXcTq70_Tez7vuEd5i5xTsU_m5D5xKPxOMlrMoaY-sopn_LwXSmO6597QOtGNb8zsRI-XlUJJKuRntAOs8hwn3kqBNscEcOPWwBbAy7noh20tWcFasFypPItcwztS08Am6puRil0276f-yn45lcexvMMTi9RQLriIgmX5jO0goGXcvWqzwT/s320/DeCamp.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Dr. DeCamp at the Elk River <b><span style="color: #783f04;">[1]</span></b></span></td></tr></tbody></table><br />Attached to Mitchel’s command was the First Michigan
Engineers and Mechanics Regiment, numbering among its ranks a Grand Rapids
surgeon named Dr. William Henry DeCamp (1825-1898) <b><span style="color: #783f04;">[3]</span></b>. DeCamp had been born in upstate New York and
moved to Grand Rapids in 1854, where he set up a medical practice. He was one of the founders of the “Grand
Rapids Lyceum of Natural History,” and had more than a hobbyist’s interest in
shells. And so it was accomplished that
sometime between April and August of 1862, somewhere in the vicinity of
Huntsville, Alabama, Dr. W. H. DeCamp, Surgeon US Army, stooped to capture a
small detachment of rebel freshwater gastropods.<p></p><p>DeCamp detailed his prisoners back behind the lines to his
friend and fellow member of the Grand Rapids Lyceum, Alfred Osgood Currier
(1817 – 1881), who forwarded a subset onward to Dr. Isaac Lea in Philadelphia
<b><span style="color: #783f04;">[4]</span></b>. And if all of this sounds vaguely
familiar to you, your memory is to be commended. For back on [<a href="https://fwgna.blogspot.com/2019/08/cpp-diary-yankees-at-gap.html" target="_blank">4Aug19</a>] I spun a very similar
yarn about Capt. S. S. Lyon, who arrived at Cumberland Gap this very same
summer of 1862, as uninvited as Dr. DeCamp, and stooped to capture a regiment
of rebel pleurocerids from the ice cold waters of East Tennessee as boldly as
Dr. DeCamp in North Alabama. And Capt.
Lyon sent his prisoners to Dr. Lea as well.</p><p>So in my essay of [<a href="https://fwgna.blogspot.com/2019/08/cpp-diary-yankees-at-gap.html" target="_blank">4Aug19</a>], I wrote, “In May of 1863, a
scant nine months later, Lea described four new species of <i>Goniobasis</i>” sent to
him by Capt. Lyon from Gap Springs <b><span style="color: #783f04;">[5]</span></b>.
Actually, to be quite precise, Lea published brief, Latinate
descriptions of 15ish <b><span style="color: #783f04;">[6]</span></b> species in that Mayish <b><span style="color: #783f04;">[7]</span></b> paper, including six
captured by “Capt. S. S. Lyon, U.S. Army,” six captured by “Dr. Wm. H. DeCamp
M.D., Surgeon US Army,” and three arrested by civilians working well behind the
lines. The six DeCamp species included
three pleurocerids from the Falls of the Ohio in Louisville, two pleurocerids
from North Alabama, and <i>Amnicola currieriana</i>, from “Huntsville.” Lea’s <i>currieriana</i> was the first specific
nomen unambiguously ascribed to what we today recognize as the hydrobioid genus
<i>Somatogyrus</i> in the drainages of The Tennessee.</p><p>Lea published a more complete description of <i>A. currieriana</i>
in 1866, together with a figure <b><span style="color: #783f04;">[8]</span></b>.
“This little species differs from all other Amnicolae which I have seen
in the broad deposit of the columella, particularly in the middle, where it
covers the umbilicus.” And indeed the
1:1 figure on Lea’s Plate 24 does show a very robust, solid little shell, no
umbilicus in evidence. Compare the
grayscale figure at lower right below to typical shells from five other
<i>Somatogyrus </i>populations more recently sampled from North Alabama. We’ll have more to say about those five
modern populations next month.</p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0DvAn7FDJXrNjCwP-MXPnCom1htypJ1npBqLu-qGwrcKH0pko_GVV7dTRc_4wsJ4Yk61d4BHixEW9vhouS3OekttXukYRhQRKpsOLlumHGlzNEUQ3qsmcr1MJlgP2XIliiVxRLUzKPIDxqZ1xncTjtbs2zjJgAmkTNrZCa7aOElFSofJ6yHtf0Jikkc-e/s100/somatogyrus-montage-small.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="75" data-original-width="100" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh0DvAn7FDJXrNjCwP-MXPnCom1htypJ1npBqLu-qGwrcKH0pko_GVV7dTRc_4wsJ4Yk61d4BHixEW9vhouS3OekttXukYRhQRKpsOLlumHGlzNEUQ3qsmcr1MJlgP2XIliiVxRLUzKPIDxqZ1xncTjtbs2zjJgAmkTNrZCa7aOElFSofJ6yHtf0Jikkc-e/s16000/somatogyrus-montage-small.jpg" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">1.5 x life size.</span></td></tr></tbody></table>It never ceases to amaze me how the War for Southern
Independence prompted such a blossoming of interest in little-brown crap snails
throughout Yankeedom 1861 – 1865. Every
gentleman of means north of the Mason-Dixon line became a Malacologist, a
Quaker, or both <b><span style="color: #783f04;">[9]</span></b>. In September of 1862,
just 8 – 10 months prior to Isaac Lea’s description of <i>A. currieriana</i>, his
younger colleague George W. Tryon had published a description of a very similar
<i>Amnicola depressa</i> from the Mississippi River at Davenport <b><span style="color: #783f04;">[10]</span></b>. And in February of 1863, three or maybe five
months prior, Theodore Gill (also of Philadelphia) had selected George Tryon’s
<i>depressus</i>, as the type of his new genus <i>Somatogyrus</i> <b><span style="color: #783f04;">[11]</span></b>.<p></p><p></p><p>Tryon added two fresh species to the genus in 1865 <b><span style="color: #783f04;">[12]</span></b>:
<i>Somatogyrus parvulus</i> from the Powell River (a tributary of the Tennessee above
Knoxville) and <i>S. aureus</i> “received from Mr. Lea several years ago” from
somewhere in the “Tennessee River.” And
we were off to the races. Between 1904
and 1915 Bryant Walker <b><span style="color: #783f04;">[13]</span></b> described 22 new species of <i>Somatogyrus</i> <b><span style="color: #783f04;">[14]</span></b>, and
other authors shoveled on as well, to the point that Burch’s 1982 Bible <b><span style="color: #783f04;">[15]</span></b>
listed 35 species of the genus, including 9 nominal species described from
North Alabama alone, all utterly indistinguishable. And alas, no lithoglyphid-Goodrich <b><span style="color: #783f04;">[16]</span></b> has subsequently
arisen to clean up the taxonomic mess.</p><p>All 35 species were described on the basis of qualitative
differences in shell morphology alone.
For example, the first species described by Walker in his 1904 paper was
<i>S. hinkleyi</i> from the Coosa River (of the Mobile Basin) at Wetumpka, AL. Walker wrote, “It differs from all the known
species in the elevated spire and conical form excepting <i><a href="https://www.fwgna.org/species/hydrobiidae/s_pennsylvanicus.html" target="_blank">S. pennsylvanicus</a></i> and
<i><a href="https://www.fwgna.org/species/hydrobiidae/s_virginicus.html" target="_blank">virginicus</a></i> herein described, but those species are much smaller and decidedly
different in contour.” <i>Somatogyrus
hinkleyi</i> is figured (1) and (2) on Walker’s plate below, <i>pennsylvanicus</i> is (15)
and (16), and <i>virginicus</i> is figured (17), (18), and (19). You be the judge.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhy-LFXScsKYu35DBewKpJszvBIpwFGLGolTIhmaelslOgk1AV0P2z9t1ybt_mFIE3UM5_QLZF8sFEpFIqYO0CRPgQdc22NBBew652RKWUXhUFoHLkROnW-Pq279i8__erK3Tkzz-NeBb3coNSflHzHbZPOPF4TSpENoJUC3jLsTlahmVNwZ6e4_c43Q-oc/s1704/Somatogyrus-Walker-1904.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1704" data-original-width="960" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhy-LFXScsKYu35DBewKpJszvBIpwFGLGolTIhmaelslOgk1AV0P2z9t1ybt_mFIE3UM5_QLZF8sFEpFIqYO0CRPgQdc22NBBew652RKWUXhUFoHLkROnW-Pq279i8__erK3Tkzz-NeBb3coNSflHzHbZPOPF4TSpENoJUC3jLsTlahmVNwZ6e4_c43Q-oc/w225-h400/Somatogyrus-Walker-1904.jpg" width="225" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Walker (1904)</span></td></tr></tbody></table><p></p><p>But let me back up and edit my opinion that all 35 nominal
species of <i>Somatogyrus</i> are “utterly indistinguishable” just slightly<b><span style="color: #783f04;"> [18]</span></b>. One of the 11 species of <i>Somatogyrus</i> that
Walker described in 1904, <i>S. umbilicatus</i> was different looking. Collected from the Coosa River at Wetumpka,
<i>S. umbilicus</i> was so lightly shelled that it had an umbilicus, as its name
telegraphs so plainly. My readership of
long memory and narrow interest may remember that Bryant Walker went on to
propose a new genus, <i>Clappia</i>, to hold his nomen <i>umbilicatus</i> in 1909<b><span style="color: #783f04;"> [19]</span></b>.</p><p>And might some of you also remember that in 2012 I reported
discovering two populations of <i>Clappia</i> in East Tennessee – one in the
Sequatchie River, and the other way up in the headwaters of the Powell in SW
Virginia <b><span style="color: #783f04;">[19]</span></b>? You can be forgiven if
your memory fails you now. But hold
those tidbits about <i>Clappia</i> tight till next month. You’re going to need them.</p><p>I suppose I might also expand my observation above that no
lithoglyphid-Goodrich has risen to clean up the <i>Somatogyrus</i> mess in these
latter days. Fred Thompson did publish a
33-page monograph on the group in 1984 <b><span style="color: #783f04;">[20]</span></b>, selecting one representative from
each of the five lithoglyphine genera he recognized in North America (<i>Gillia,
Fluminicola, Somatogyrus, Clappia</i>, and <i>Lepyrium</i>) for detailed anatomical
review. But here is a telling quote from
the second paragraph of Thompson’s introduction:</p><p></p><blockquote><span style="font-size: x-small;">“This study stems from two independent investigations. The first was an attempt to determine
species-group characteristics within <i>Somatogyrus</i>, a genus containing many
species (Burch & Tottenham 1980).
The study was tabled temporarily because very little anatomical
diversity was discovered among the species examined. Independently I examined the anatomy of <i>Lepyrium
showalteri </i>(Lea), a snail previously placed in a monotypic family of uncertain
affinity. Its soft anatomy was found to
be hardly distinguishable from that of <i>Somatogyrus</i>.”</span></blockquote><p></p><p>Thompson never picked his first “independent investigation”
back up off the table. Apparently as far
as he could ever tell, all 35 of the nominal <i>Somatogyrus</i> species catalogued in
the Burch Bible were as utterly indistinguishable anatomically as they were
shell morphologically. In fact, the only
soft-part difference of any sort he reported across all five lithoglyphine
genera was the presence of a papilla on the penis of <i>Gillia</i> and
<i>Fluminicola</i>. Even the penial morphology
of <i>Somatogyrus</i>, <i>Clappia</i>, and <i>Lepyrium</i> is indistinguishable, even by the most
discerning splitter – just a simple, pointy hose.</p><p>Had Thompson understood the hydrobiids as Goodrich
understood the pleurocerids, at this point he would have synonymized the entire
35-member crap-pot of <i>Somatogyrus</i> down an order of magnitude to three species
and a subspecies. Instead, he added an
appendix of his 1984 paper for the description of yet another utterly
indistinguishable species of <i>Somatogyrus</i> from Georgia, <i>S. rheophilus</i>. Fred Thompson was no Calvin Goodrich. And it is through the dusky twilight of
Walker and Burch that we still walk to this day.</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-g_yUEtHbuYC_tI5-DD6TtHWu3YxRQyHUV8jyrPgWERFkJfU9O_IzkSjUupp8PstXKEgoPAl8FH5wrfqYGz46e4iG5nPKhvVZkuOAwXfmJFH8dh-GiRS4xL3zjSEIQ5WUicUpp1dcBJE5zJB4o4hLtF0QFujS6a9MdN5RQXIXHIhtSnMWQsRjrtNQpO6g/s1977/S_rheophilus-anat.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1219" data-original-width="1977" height="197" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-g_yUEtHbuYC_tI5-DD6TtHWu3YxRQyHUV8jyrPgWERFkJfU9O_IzkSjUupp8PstXKEgoPAl8FH5wrfqYGz46e4iG5nPKhvVZkuOAwXfmJFH8dh-GiRS4xL3zjSEIQ5WUicUpp1dcBJE5zJB4o4hLtF0QFujS6a9MdN5RQXIXHIhtSnMWQsRjrtNQpO6g/s320/S_rheophilus-anat.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Fig 43 of Thompson <b><span style="color: #783f04;">[20]</span></b></span></td></tr></tbody></table><br />One might imagine, from all the taxonomic excitement
generated by Bryant Walker, his forebears, contemporaries and successors, that
populations of <i>Somatogyrus</i> must have been common throughout the Tennessee River
basin in the early 20th century. That is
certainly not true today, and I’m not sure it was true even back then. Pilsbry & Rhoads (1896) reported a
<i>Somatogyrus</i> population in the “Nolachucky River near Greeneville” which I have
not been able to verify <b><span style="color: #783f04;">[21]</span></b>. Nor can I
confirm the populations that Walker (1904) reported in the Tennessee River at
Knoxville, or in its tributary the Holston.<p></p><p>But here is an important point. The five major tributaries of the Tennessee
River above Knoxville, from north to south, are the Powell, the Clinch, the
Holston, the Nolichucky, and the French Broad.
Tryon described his (1865) <i>S. parvulus</i> from the Powell, where
populations still hang on today. Two
generations later, Pilsbry & Rhoads (1896) and Walker (1904) identified
populations collected from the Holston 20 miles south of the Powell and the
Nolichucky 20 miles south of the Holston as <i>Somatogyrus aureus</i>. Between Tryon and Pilsbry came the immortal
team of Dr. James Lewis and Miss Annie E. Law.</p><p>Dr. James Lewis (1822 – 1881) was a dentist/conchologist
from Mohawk, NY, who was reputed to have one of the greatest private
collections of American land and freshwater shells in existence at the time of
his death. According to his obituary in
The American Naturalist <b><span style="color: #783f04;">[22]</span></b>, he “arranged and classified many public
collections, among which were the American fresh-water shells in the
Smithsonian Institution, the last critical revision of which was made by him.” Really?
He should be better known today than he is.</p><p>Miss Annie Elizabeth Law (1842 – 1889), school teacher and
alleged Civil War spy<b><span style="color: #783f04;"> [23]</span></b>, was born in England but spent most of her life in
the vicinity of Maryville, Tennessee <b><span style="color: #783f04;">[24]</span></b>.
“Through Col. W. G. McAdoo, of Knoxville, she was introduced to Dr.
James Lewis, of Mohawk, New York, who wished her to collect shells. She had from childhood a taste for shells,
mineralogy, entomology, botany, in fact everything connected with nature,” and
so was apparently eager to comply. Over
a period of some two years, Miss Law walked 20 miles of the Holston River “from
Little River Shoals to Chota Shoals,” collecting both the bivalves and the
gastropods she discovered along the way, posting them to her sponsor in Mohawk,
NY. In his 1871 report of her expedition
<b><span style="color: #783f04;">[25]</span></b>, Lewis observed:</p><p></p><blockquote><span style="font-size: x-small;">“I have from Miss Law numerous shells identical with
<i>Somatogyrus parvulus</i>, Tryon, found, at very low stages of water, in little
pools left by the receding water along swift, shallow, gravelly portions of the
Holston. Less abundantly a somewhat
larger shell agreeing with <i>S. aureus</i> Tryon.
Also larger shells identical with “<i>Amnicola Currieriana</i>, Lea,” found in
still water, along muddy portions of the Holston, near the shore. They are, without doubt different ages of one
species. Mr. Leas name for the species
takes precedence.”</span></blockquote><p></p><p>Yes, Dr. James Lewis identified <i>Somatogyrus currierianus</i>
(Lea 1863) in East Tennessee. And he
synonymized both <i>parvulus</i> (Tryon 1865) and <i>aureus</i> (Tryon 1865) underneath it.</p><p>That brings our essay full circle, back to the exciting
summer of 1862, and Dr. W. H. DeCamp standing on the banks of the big-river
Tennessee somewhere in the vicinity of Huntsville. <b>The key to understanding the <i>Somatogyrus</i> of the
entire Tennessee River drainage is to understand <i>Somatogyrus currierianus </i>in
North Alabama.</b> Next time, a fresh adventure!</p><p><u>Notes</u></p><p><b><span style="color: #783f04;">[1] </span></b>I have taken most of the historical narrative in the
first two paragraphs above, as well as the interesting figure, were from:</p><p></p><ul style="text-align: left;"><li>Hoffman, M. (2007) My Brave Mechanics: The First Michigan
Engineers and their Civil War. Wayne
State University Press, 470 pp.</li></ul><p></p><p><b><span style="color: #783f04;">[2]</span></b> Mitchel was promoted to command the entire Department of
The South, and transferred to Beaufort, SC, where he died almost immediately of
Yellow Fever. Why was Mitchel in
Beaufort? See:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Many Invasions of Hilton Head [<a href="https://fwgna.blogspot.com/2015/12/the-many-invasions-of-hilton-head.html" target="_blank">16Dec15</a>].</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> This is the fourth time that the name of Dr. W. H.
DeCamp has come up in the 25 year record of this blog. We focused a great deal of attention on
<i>Goniobasis decampii</i> Lea 1863/66 <b><span style="color: #783f04;">[6]</span></b> in “A House Divided” [<a href="https://fwgna.blogspot.com/2020/05/a-house-divided.html" target="_blank">10May20</a>], and on
<i>Campeloma decampi</i> (Binney 1865) in “Fun With Campeloma” [<a href="https://fwgna.blogspot.com/2021/05/fun-with-campeloma.html" target="_blank">7May21</a>]. <i>Lymnaea decampi</i> Streng 1906 also garnered a
brief mention in footnote [3] of “Malacological Mysteries I: The type locality
of Lymnaea humilis” way back in [<a href="https://fwgna.blogspot.com/2010/02/malacological-mysteries-type-locality.html" target="_blank">25June08</a>].</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> For a brief biography of the “Nestor of American
Naturalists” see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Isaac Lea Drives Me Nuts [<a href="https://fwgna.blogspot.com/2019/11/isaac-lea-drives-me-nuts.html" target="_blank">5Nov19</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Lea, Isaac (1863) Descriptions of fourteen new species
of Melanidae and one Paludina.
Proceedings of the Academy of Natural Sciences of Philadelphia 15: 154 –
156.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Lea apparently intended to include a description of
<i>Melania decampii</i> from Huntsville in his paper of Mayish<b><span style="color: #783f04;"> [7]</span></b> 1863, but that
paragraph was omitted. In his follow-up
paper of 1866 <b><span style="color: #783f04;">[8]</span></b> he stated that the Latinate description of <i>Melania decampii</i>
had been published previously in “Proc. Acad. Nat. Sci., 1863, p. 154” but it
was not. Was Lea’s statement an overt
fabrication, or just sloppiness? Either
way, stuff like this drives me nuts.
Absolutely nuts <b><span style="color: #783f04;">[4]</span></b>.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Lea apparently read his paper in May of 1863, and “May”
is printed on the bottom of the published pages, but the front of the published
volume says, “June and July, 1863.”</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Lea, Isaac (1866)
New Unionidae, Melanidae, etc. chiefly of the United States. Journal of the Academy of Natural Sciences of
Philadelphia (New Series) 6: 113 – 187.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> For more about the malacologists of Yankeedom 1861 –
1865, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Ferrissia fragilis (Tryon 1863) [<a href="https://fwgna.blogspot.com/2019/02/ferrissia-fragilis-tryon-1863.html" target="_blank">6Feb19</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Tryon, G. W. (1862)
Notes on American fresh water shells, with descriptions of two new
species. Proceedings of the Academy of
Natural Sciences of Philadelphia 14: 451 – 452. I really think that the Mississippi River <i>Somatogyrus</i> populations are best identified today as <i><a href="https://www.fwgna.org/species/hydrobiidae/s_integra.html" target="_blank">Somatogyrus integra</a></i> (Say 1829).</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Gill, T. (1863) Systematic arrangement of the mollusks
of the family Viviparidae, and others, inhabiting the United States.
Proceedings of the Academy of Natural Sciences of Philadelphia 15: 33 – 40.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> Tryon, G. W. Jr. (1865) Descriptions of new species of <i>Amnicola,
Pomatiopsis, Somatogyrus, Gabbia, Hydrobia</i> and <i>Rissoa</i>. American Journal of Conchology 1: 219-222, pl
22, figs 5-13.</p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> Here’s a brief biography of Michigan’s Father of
Malacology:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Bryant Walker’s Sense of Fairness [<a href="https://fwgna.blogspot.com/2012/11/bryant-walkers-sense-of-fairness.html" target="_blank">9Nov12</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Bryant Walker’s
papers on <i>Somatogyrus</i>:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Walker, B. (1904) New
species of <i>Somatogyrus</i>. Nautilus 17: 133
- 142.</li><li>Walker. B. (1906) New
and little known species of Amnicolidae.
Nautilus 19: 97-100, 114-117.</li><li>Walker, B. (1909)<span style="mso-spacerun: yes;"> </span>New
Amnicolidae from Alabama.<span style="mso-spacerun: yes;"> </span>Nautilus 22:
85 - 90.<span style="mso-spacerun: yes;"> </span></li><li>Walker, B. (1915) Apical characters in <i>Somatogyrus</i> with
descriptions of three new species.<span style="mso-spacerun: yes;"> </span>The
Nautilus 29: 37 - 41, 49 - 53.</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> This is a difficult work to cite. J.B. Burch’s North
American Freshwater Snails was published in three different ways. It was initially commissioned as an
identification manual by the US EPA and published by the agency in 1982. It was also serially published in the journal
Walkerana (1980, 1982, 1988) and finally as a stand-alone volume in 1989
(Malacological Publications, Hamburg, MI).</p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> A “lithoglyphid” is a member of the modern family
Lithoglyphidae, previously a subfamily of the Hydrobiidae <b><span style="color: #783f04;">[17]</span></b>, bearing
featureless anatomy and shell morphology, characterized by nothing
whatsoever. And Calvin Goodrich was the
twentieth-century hero who brought science to the classification of the
Pleuroceridae, which was an order of magnitude worse. For more, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Legacy of Calvin Goodrich [<a href="https://fwgna.blogspot.com/2007/01/legacy-of-calvin-goodrich.html" target="_blank">23Jan07</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> Wilke, Haase, Hershler, Liu, Misof, and Ponder (2013)
Pushing short DNA fragments to the limit: Phylogenetic relationships of
“hydrobioid” gastropods. Molec. Phyl.
Evol. 66: 715 – 736. For a review, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Classification of the Hydrobioids [<a href="https://fwgna.blogspot.com/2016/08/the-classification-of-hydrobioids.html" target="_blank">18Aug16</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> Well, to be fair, Walker described two species of
<i>Somatogyrus</i> with distinctive shell morphology: <i>umbilicatus</i> in 1904 and
<i>biangulatus</i> in 1906. The latter seems to
have been endemic to the main Tennessee River at Muscle Shoals, and now (I
fear) extinct.</p><p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> See my 2012 series of essays for a study of Bryant
Walker, <i>Somatogyrus</i>, <i>Clappia</i>, and the relationships between all three:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Bryant Walker’s Sense of Fairness [<a href="https://fwgna.blogspot.com/2012/11/bryant-walkers-sense-of-fairness.html" target="_blank">9Nov12</a>]</li><li>On Getting Clappia in Tennessee [<a href="https://fwgna.blogspot.com/2012/12/on-getting-clappia-in-tennessee.html" target="_blank">3Dec12</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[20] </span></b>Thompson, F.G. (1984) North American freshwater snail
genera of the hydrobiid family Lithoglyphinae.
Malacologia 25: 109 – 141.</p><p class="MsoNormal"><b><span style="color: #783f04;">[21]</span></b> Pilsbry, H. & Rhoads, S. (1896) Contributions to the Zoology of Tennessee,
Number 4, Mollusca. Proc. Acad. Nat. Sci. Phila. 1896: 487-506.</p><p class="MsoNormal"><b><span style="color: #783f04;">[22] </span></b>Call, R.E. (1881) Memoriam of Dr. James Lewis. The American Naturalist 15: 506-508.</p><p class="MsoNormal"><b><span style="color: #783f04;">[23]</span></b> I have not been able to confirm the allegations of
spying, and I strongly suspect it was for the Union, but I don’t care, I would
have really loved to meet Miss Annie E. Law.
Hell, if I was 120 years younger, I would have proposed.</p><p class="MsoNormal"><b><span style="color: #783f04;">[24]</span></b> I have pieced my biographical background on Miss Law
from a variety of secondary sources, including Tucker Abbott’s (1973) American
Malacologists, The Poppe’s conchology.be website, and Nautilus 40: 132 – 133.</p><p class="MsoNormal"><b><span style="color: #783f04;">[25]</span></b> Lewis, J. (1871)
On the shells of the Holston River.
American Journal of Conchology 6: 216-226.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-41142634345247860212023-06-06T12:57:00.005-04:002023-11-24T18:55:38.300-05:00The Mystery Snail Color Genetics Project<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023c) The Mystery Snail Color Genetics Project. Pp 63 – 74 <b>in</b> The Freshwater Gastropods of North America Volume 7, <i>Collected in Turn One, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Who among you, my vast and far-flung readership, has not at
least once in your life lingered at the face of a hobbyist aquarium to enjoy a
“Mystery Snail?” Show of hands? One or two of you in the back?</p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjb25hmUGByPUONbdT75pBSiptMTDLsYHeVHGp4C-NS7xrUH3_UJU49xJOTG7GQYROd6UWnnUgs2hy4aTbxABRH2FFy8liGbzfht0cAt9IUJb3suumSASnOHdcbVSl4TwRHfYv-An8Tz6ldY6OVd6nEWmbG5PT6qb6N9hdpjSFvxqlaO2SzoK9fvBKX-A/s1327/MSCGP-voss.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1327" data-original-width="983" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjb25hmUGByPUONbdT75pBSiptMTDLsYHeVHGp4C-NS7xrUH3_UJU49xJOTG7GQYROd6UWnnUgs2hy4aTbxABRH2FFy8liGbzfht0cAt9IUJb3suumSASnOHdcbVSl4TwRHfYv-An8Tz6ldY6OVd6nEWmbG5PT6qb6N9hdpjSFvxqlaO2SzoK9fvBKX-A/w148-h200/MSCGP-voss.jpg" width="148" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Ms. Rachel Voss</span></td></tr></tbody></table>OK, a bit of introduction may be helpful before we get down
to business this month. The common name
“mystery snail” is today almost universally <b><span style="color: #783f04;">[1]</span></b> applied to <i>Pomacea diffusa</i>, the
most popular gastropod in the home aquarium worldwide, a (relatively) small
South American ampullariid domesticated in the late 1960s <b><span style="color: #783f04;">[3]</span></b> for the
international pet trade. Such snails
were generally identified as <i>Pomacea bridgesii</i> (Reeve 1856) until around 2007,
when a team of our colleagues <b><span style="color: #783f04;">[4]</span></b> suggested that the nomen <i>diffusa</i>, proposed as
a subspecies of <i>P. bridgesii</i> by the German biologist Werner Blume in 1957 <b><span style="color: #783f04;">[5]</span></b>,
might merit recognition at the full species level.<p></p><p>Although small bodied by the standards of the Ampullariidae,
and hence not as voracious of aquarium plants, nor as dangerous as pests upon
escape into the wild <b><span style="color: #783f04;">[6]</span></b>,<i> Pomacea diffusa</i> are still large enough to have a
personality, which is, in the eyes of many an adoring enthusiast,
charming. Open my essay of [<a href="https://fwgna.blogspot.com/2017/12/pet-shop-malacology.html" target="_blank">21Dec17</a>] in
a new window for more context, and a bit of additional biological background on
mystery snails in the home aquarium.</p><p>Some not-insubstantial fraction of the popularity of mystery
snails derives from their color polymorphism.
Although I have seen at least 15 – 20 named color varieties on the
market, consensus seems to suggest eight distinct phenotypes, some with
multiple names. These are depicted in
Ms. Brookana Ashley Patton’s colorful figure below, with a standard name
suggested for each: gold, jade, ivory, blue, chestnut, brown/black, magenta,
and purple.</p><p>A simple Mendelian hypothesis suggests itself immediately,
does it not? Three loci, each with two
alleles, would yield eight phenotypic categories quite splendidly. One of those loci must obviously control body
color, with albinism (<b>a</b>) recessive under pigmented (<b>A</b>), if the pattern seen
almost everywhere <b><span style="color: #783f04;">[7]</span></b> throughout the remainder of the animal kingdom is
followed in ampullariid snails.</p><p>The other two loci seem to control the coloration of the
shell: background color (<b>Y</b>) and striping or color banding overtop of it
(<b>S</b>). A peculiarity of this system is
that in most other animals, typically, a mutation at the locus assigned to
albinism blocks all color production, everywhere. Three of the eight varieties of mystery
snails, however (gold, chestnut, and magenta), demonstrate colorless bodies but
colored shells.</p><p>The invasive pests <i>Pomacea canaliculata </i>and <i>P. maculata</i> have
well-known “golden” variants with a colorless body and plain yellow shell. The shell and the body phenotypes seem to be
inherited together, as a simple Mendelian recessive trait <b><span style="color: #783f04;">[8]</span></b>. The “Giant Columbian Rams Horn” <i>Marisa
cornuarietis</i> also has a “golden” variant, inherited as a simple Mendelian
recessive, but in this case the plain, unstriped yellow shell is born by a
snail with a pigmented body <b><span style="color: #783f04;">[9]</span></b>.</p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsxdgOrpq4Uzq2638pGyj2xjiclmOinEAfFke0x_kq_Beal4TS9VO9kq0Hj770S9Tb9f1YVBrr8QwfCUX74ar9k5V8-0qOCIDfSH_CnuGnI9AnJDyX60ma25ezOfyVfVq7ooEvFuzeAC4i4weJH1Qi0bsr1PLL9me_bAiYV0Nq3hYdP2lNBeFQSyQTdQ/s894/MSCGP-brookana.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="894" data-original-width="649" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsxdgOrpq4Uzq2638pGyj2xjiclmOinEAfFke0x_kq_Beal4TS9VO9kq0Hj770S9Tb9f1YVBrr8QwfCUX74ar9k5V8-0qOCIDfSH_CnuGnI9AnJDyX60ma25ezOfyVfVq7ooEvFuzeAC4i4weJH1Qi0bsr1PLL9me_bAiYV0Nq3hYdP2lNBeFQSyQTdQ/w290-h400/MSCGP-brookana.jpg" width="290" /></a></div>In the mystery snail <i>Pomacea diffusa</i>, the rainbow of
phenotypes commonly observed in the aquarium suggests one locus analogous to
that seen in <i>P. canaliculata</i> and <i>M. cornuarietis</i>, the dominant wildtype allele (<b>S)</b> encoding dark stripes or bands of pigmentation covering the shell. The recessive (<b>s)</b> seems to encode no banding or
striping, uncovering the yellow or “golden” background shell color. I am reminded of the banding locus in the
European land snail, <i>Cepaea</i>, which became such an important model organism in
the early development of population genetics <b><span style="color: #783f04;">[10]</span></b>.<br /><p></p><p></p>As for that second shell color locus, variation in
background color independent of banding above it or body pigmentation below is
unique to <i>Pomacea diffusa</i>, in my experience.
I have never seen anything like it anywhere in The Mollusca. But two alleles again seem to be involved:
let’s suggest a dominant yellow background (<b>Y</b>) and a recessive colorless
(<b>y</b>). The implication of the model is
that as many as three separate biochemical pathways seem to control mystery
snail coloration, yielding eight phenotypes, such that the wildtype brown/black
phenotype is encoded <b>A_Y_S_</b> and the completely colorless ivory variety <b>aayyss</b>. If the model holds.<p></p><p>The three-locus model I have outlined above is not new or
original with me. It seems to have been
a part of the lore of mystery snail husbandry for many years <b><span style="color: #783f04;">[11]</span></b>. And there are most certainly some very clever
and resourceful snail breeders somewhere in the world who could confirm it in a
heartbeat. But to this day, no formal
test has ever been published. The
entire, lovely system – all those exciting phenotypes and the
intellectually-gratifying hypotheses that go with them – remain anecdotal,
untested, and undocumented in the world at large.</p><p>Because, in all fairness, those clever and resourceful snail
breeders who developed all those lovely gold and purple and jade and ivory
snail varieties have reaped some not-insignificant financial reward for their
time and effort, would like to reap more, and consider the genetics behind
their product a trade secret. I
understand that.</p><p>But doggone it, I myself am a professional mollusk
geneticist, retired and bored, with nothing better to do with my life than
science. I have a testable hypothesis
about the inheritance of color polymorphism in a promising freshwater gastropod
model, and I want to see it tested. And
if that hypothesis could be confirmed, all those striking genetic markers could
be powerful tools to answer all sorts of additional questions about the biology
of the Ampullariidae, a fascinating family of God’s critters, like for example,
the consequences of multiple insemination, the potential for sperm competition,
and the capacity for sperm storage, see five paragraphs further down.</p><p>The experiments necessary to confirm our three-locus model
for the inheritance of color polymorphism in <i>Pomacea diffusa</i> are not
complicated. But they require time,
patience, attention to detail, and some significant experience with a very
specialized little corner of animal husbandry.
The ampullariid diet is non-trivial.
The egg laying, the hatching, and the rearing of juveniles all require
special techniques. And the experiment
will require space. Mystery snails are
substantial animals – their culture requires relatively large volumes of water.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhS_j3aB6LuEJmt89GtqMwPQFEjM1wFhbWGq81zewYfGIy-97SjrdwhdjHiAe6j93OJG48sbSThyCTVI2O8yRz4gByqnmjCS6ZtmV4qQWz0GslfcZedu5TvOxVO3hfvOBVBon2y6VC9VfgRQSMXvrUs4UCAJ68ODLr6CHVELOKM79DHqEjyul4fPVNDig/s4032/MSCGP-Kyra1.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3024" data-original-width="4032" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhS_j3aB6LuEJmt89GtqMwPQFEjM1wFhbWGq81zewYfGIy-97SjrdwhdjHiAe6j93OJG48sbSThyCTVI2O8yRz4gByqnmjCS6ZtmV4qQWz0GslfcZedu5TvOxVO3hfvOBVBon2y6VC9VfgRQSMXvrUs4UCAJ68ODLr6CHVELOKM79DHqEjyul4fPVNDig/w320-h240/MSCGP-Kyra1.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Kyra's basement, May 2020</span></td></tr></tbody></table><p></p><p>I cultured <i>Physa</i> and a variety of other pulmonates in my lab
for many years, and a couple prosobranch species as well <b><span style="color: #783f04;">[12]</span></b>, and was
repeatedly surprised, perhaps even dismayed, by the requirement of simple space
– just open, flat space on shelf and lab bench.
There were times in my career that I was covering hundreds of square
feet culturing snails with a maximum adult size of 30 mg. Adult mystery snails are two orders of magnitude
larger than <i>Physa</i>. Am I going to go hat
in hand and ask my wife for thousands of square feet in our suburban home to
culture <i>Pomacea</i>?</p><p>So back in 2017, doing research for a six-part series on
freshwater gastropods in the home aquarium <b><span style="color: #783f04;">[14]</span></b>, I started lurking about in <b><span style="color: #783f04;">[15]</span></b> Facebook
groups formed by mystery snail enthusiasts.
There were at that time 1,818 members of a Facebook group called
“Mystery Snail Addiction,” 3,166 members of a group called “Mystery Snails and
Aquatic Lovers,” and 5,442 members of a group called “Snails, Snails,
Snails.” And an idea dawned on me.</p><p>The idea is called “crowdsourcing.” Paging through screenfuls of excited chatter
about mystery snails, with images and videos about every conceivable aspect of
their life habit and zany antics, it occurred to me that I might be able to
attract a large number of talented and enthusiastic volunteers for what I
decided to call “The Mystery Snail Color Genetics Project.”</p><p>So, I whipped up a modest website of eleven pages, including
biological background, genetic model, and three pages of experimental
design. In broad outline, I guided
potential collaborators through a trihybrid testcross, starting with an ivory
line (<b>aayyss</b>) and a brown/black (<b>AAYYSS</b>), backcrossing the F1 to the ivory to
test for linkage. The biggest challenge
was that, absent any data on the question, I felt as though we needed to assume
that females store sperm for life, and hence virgin females would be
required. Hit the link below in a new
window to see the website if you are curious.
Or a pdf of the entire website is available as FWGNA Circular Number 7
from footnote <b><span style="color: #783f04;">[16]</span></b> below.</p><p style="text-align: center;"><span style="font-size: medium;"><a href="https://www.fwgna.org/dillonr/MSCGP/index.html" target="_blank">MSCGP</a></span></p><p>Notice in particular that step #1 for all new recruits to
the MSCGP army was to email me. I really
wanted to establish a direct relationship with every volunteer and try to learn
a bit about each of them personally. I
didn’t want to discourage anybody, but I did want to make it clear that what we
are doing together is real science. We
will have standards. No screwing around.</p><p>I announced the MSCGP to the three Facebook groups on
November 8, 2018, appealing for volunteers, pointing interested parties to the
website, and inviting email inquiries.
And braced myself at my laptop for the excited torrent of likes, loves,
emojis, comments, questions and wisecracks I felt sure would pour forth.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjs342qQH8QPVqyNlOHNPkn_RWa820NA2OQwNWrzou4jv-fGo19NFFLS-uTMqZpaw2ckTJiLBzDVxW5mG9rhK9UcPa_-1-m4GtaRwV6rCoLO5iu61-38i6HIbPxj-cG__BW7r95193pC3VT3MRL0S5zg-boV6euCKj6L-slInpotHHErHmeUA2b8mK1Ag/s1354/MSCGP-FB-post.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1354" data-original-width="1346" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjs342qQH8QPVqyNlOHNPkn_RWa820NA2OQwNWrzou4jv-fGo19NFFLS-uTMqZpaw2ckTJiLBzDVxW5mG9rhK9UcPa_-1-m4GtaRwV6rCoLO5iu61-38i6HIbPxj-cG__BW7r95193pC3VT3MRL0S5zg-boV6euCKj6L-slInpotHHErHmeUA2b8mK1Ag/s320/MSCGP-FB-post.jpg" width="318" /></a></div><p></p><p>And in fact, my posts on those three FB sites did reap 6
likes and 4 comments. Zero shares, but I
don’t know what a “share” is, in this context, so that doesn’t matter, does
it? How many followers do I have, I
wondered? Am I an influencer yet?</p><p>But I will admit to considerable disappointment when just
one of those 6 likers and 4 commenters emailed me directly, a nice young man in
Australia, who said he would love to become involved, but no ivory mystery
snails were available in his country.
And my posts disappeared off the bottom of the feeds of all three of those FB
sites in a matter of hours, gone without a trace.</p><p>I received a second inquiry in January of 2019, a third in
August, and then two more in November of 2019, a year after I posted my appeal
for volunteers. This was not the
response that I was expecting, either in quantity or in quality.</p><p>All of these inquiries came from folks who had googled up
the MSCGP website and were curious to hear any results we might have obtained. All were keeping mystery snails as pets, and
had some success in reproduction, and were intrigued by color variation in the
offspring. No results so far, I always
replied cheerily, but would you like to volunteer? And one of them did.</p><p>Ms. Kyra Hall, who was one of the two who emailed me in
November of 2019, was the first serious volunteer recruited into the Mystery
Snail Color Genetics Project. She
ultimately pushed the effort further than any other collaborator to the present
day, hatching out quite a few pure ivory sibships and attempting to rear them
in isolation. She actually got to the
point that she needed true breeding wildtype females, to lay clutches of
brown/black offspring with which to cross her ivories. And it was not until this late date, well
into the winter of 2019, that it occurred to me that developing a true-breeding
dominant line might be more difficult than a true-breeding recessive.</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjP7BLhxoun_ze-mXbyakXCy5QasHkZ6qR3KKsfURhqYjW1uBgY3tMq8wL3vPVCrsZoRj7yam5AtBNWnKAvPu1VjDZhW-Zev40Iyz-OZB0noDJtlvN4Dzlh3WVKSuFyxV67Jcw_vXxb-ShNyQMAz_zQt00yNsk-WQw9USDJqs7ba0HyjGPia54jYVwAfA/s3506/MSCGP-Beach-Blvd.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2630" data-original-width="3506" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjP7BLhxoun_ze-mXbyakXCy5QasHkZ6qR3KKsfURhqYjW1uBgY3tMq8wL3vPVCrsZoRj7yam5AtBNWnKAvPu1VjDZhW-Zev40Iyz-OZB0noDJtlvN4Dzlh3WVKSuFyxV67Jcw_vXxb-ShNyQMAz_zQt00yNsk-WQw9USDJqs7ba0HyjGPia54jYVwAfA/w200-h150/MSCGP-Beach-Blvd.jpg" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Beach Blvd, Jacksonville.</span></td></tr></tbody></table>We have absolutely no idea on the genetic background of the
mystery snails we find for retail sale in aquarium stores. What would make anybody assume that a snail
demonstrating the dominant phenotype was true-breeding? In fact, it might be more fun if they
weren’t, so that dominant mothers might lay interestingly diverse and colorful
F1 sibships. The more I thought about
it, I could see some argument for the mysterious snail breeders at the Mystery
Snail Factory to purposefully outcross their brown/black stocks before retail
sale, if for no other reason than to prevent competitors from developing such
stocks on their own.<p></p><p>Might a few generations in the wild select out any weirdo
genes bred into Pomacea diffusa stocks for commercial purposes? Might a naturalized population be the best
source of <b>AAYYSS</b> broodstock? Hmmm. <i>Pomacea diffusa </i>populations are not commonly
reported in the wild <b><span style="color: #783f04;">[17]</span></b>.</p><p>I had known the late Bill Frank for many years, primarily as
the steward of the quirky and entertaining jaxshells.org website. Bill discovered a naturalized population of
<i>Pomacea diffusa</i> inhabiting drainage ditches by Beach Boulevard in East
Jacksonville in 2006, and posted the discovery on jaxshells.org, and it is
probably my browsing across his black, blue, and wisteria-hued webpage [<a href="https://jaxshells.org/bridge.htm" target="_blank">html</a>] that brought the phenomenon to my attention.</p><p>So, I emailed my buddy Bill, and asked him if he had ever
seen any color polymorphism in his Beach Blvd population of <i>P. diffusa</i>. And he said no. And so it came to pass that on December 5,
2019, I pulled into the Denny’s parking lot for my rendezvous with Bill. The man was as colorful as the palate of his
webpages. I cannot remember the last
time I met anybody, at any station young or old, so dedicated, so enthusiastic,
so enthralled by trash snails in a weedy ditch.
This world needs more Bill Franks <b><span style="color: #783f04;">[18]</span></b>.</p><p>And the English thesaurus needs more choices under the noun,
“ditch.” Here at home in the Carolina
Lowcountry, our drainage ditches are dug to carry away stormwater. They are almost always dry. But down in Florida, it is my impression that
most ditches are mostly wet, and often transmit significant volumes of
groundwater. The water in the ditches
that Bill showed me that morning by Beach Blvd was demonstrating some
non-negligible flow, even though it had not rained recently, the water clear
and coolish <b><span style="color: #783f04;">[19]</span></b>.</p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1SfzjWqYhhBFE_6f7SJ54pksv6yFnbRnJ4huue93L0ctzp3crRildbuFPK8Dcmfek34sWCleab6JjgJuLduP_B3eU1NfdwbE0tvOYaoeYQcveV114euS7rie9vo0duRRu4hMPvTXcpT6Jh9UzIgPZzn_8-EMIH1A7xbXVKbptqDOb4T6fnt5HwuOQgg/s3647/MSCGP-P_diffusa.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="2735" data-original-width="3647" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj1SfzjWqYhhBFE_6f7SJ54pksv6yFnbRnJ4huue93L0ctzp3crRildbuFPK8Dcmfek34sWCleab6JjgJuLduP_B3eU1NfdwbE0tvOYaoeYQcveV114euS7rie9vo0duRRu4hMPvTXcpT6Jh9UzIgPZzn_8-EMIH1A7xbXVKbptqDOb4T6fnt5HwuOQgg/w200-h150/MSCGP-P_diffusa.jpg" width="200" /></a></div>Bill and I were able to find a dozen adult <i>P. diffusa</i> in
about two hours’ effort, combing through the ditches on both sides of the
road. Against the background of his
long-term observations of the population dynamics, Bill considered this result
a very good catch. I carried our fresh
wildstock back to Charleston that evening and sent a subset by overnight
express to Kyra the next day.<p></p><p>The females among them were, in fact, very healthy and fecund,
and Kyra was able to hatch quite a few nice clutches of 100% wildtype
brown/black progeny. But alas, her
efforts to affect an ivory x brown/black cross did not come to fruition.</p><p>Kyra had to move into an apartment in late 2020, effectively
bringing to a close her budding career in gastropod genetics. “Life got in the way,” she explained. But as annus horribilis 2020 unfolded, from
worldwide coronavirus panic to nationwide political ignominy, I was somewhat
surprised and really quite gratified to receive an additional nine email
inquiries from potential volunteers, a broad assortment of hobbyists who had
googled for information on the inheritance of color polymorphism in mystery
snails and happened upon the MSCGP website.</p><p>And again, although most of those nine did not ultimately
initiate experiments, as far as I know, several of them did, at least one or
two of whom made serious efforts. And in
2021 I received inquiries from another ten potential volunteers, a subset of
whom initiated experiments, a subset of whom made serious efforts. And in 2022 I received seven additional
inquiries. So that, as 2022 came to a
close, I had exchanged at least some correspondence with a total of 31
potential volunteers for the mystery snail color genetics project. I should at this point acknowledge Joanna
Walthuis, Leigh Charest, John Hynes, and Rachel Voss for significant
contributions of time and effort to the MSCGP at intervals during our history.</p><p>On February 16, 2023 I sent out a group email to the entire
list of N=31 in my MSCGP address book, just to see what the current status of
our project might be. I received ten
replies, four of which came from volunteers who still have active experiments
underway. The six respondents who have
retired from the field were evenly split, three citing technical difficulties
and three reporting, like Kyra, that “life got in the way.”</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVnLcIrEjlbX1-vaM8ok5QpYLs2BrTACDqgeOwVkL5j9mE9OhKv8gFwA4RDQldePfhzgfaijSO0GBpEhpZo0QDAIY9mbN07kIOBIRCUAvYgY6PmbmnLt-vCQhW_c57BsI69LoN0GtsqeDSXcWXEPH2KsYcaCcvd7Qnn5mzEGQx5At5ZNU3NGw5_3Sw8A/s4032/MSCGP-kyra2.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3024" data-original-width="4032" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiVnLcIrEjlbX1-vaM8ok5QpYLs2BrTACDqgeOwVkL5j9mE9OhKv8gFwA4RDQldePfhzgfaijSO0GBpEhpZo0QDAIY9mbN07kIOBIRCUAvYgY6PmbmnLt-vCQhW_c57BsI69LoN0GtsqeDSXcWXEPH2KsYcaCcvd7Qnn5mzEGQx5At5ZNU3NGw5_3Sw8A/s320/MSCGP-kyra2.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Kyra's Library, February 2020</span></td></tr></tbody></table>The bottom line remains, however, blank. Here about halfway through the fifth year of
the Mystery Snail Color Genetics Project, <b>we have yet to record our first
datum.</b> The consensus from the rank and
file seems to reinforce a concern I myself have harbored since I first outlined
the experimental design back in 2018. Rearing
pairs of snails in cups, even large (20 oz ones) may require an impractical
frequency of water change, and scaling up to one-gallon containers may require
an impractical amount of space. I am
just not sure that the pretty experiment I have outlined on the chalk board can
be conducted in a private residence, by a private citizen with a job other than
snail farming.<p></p><p>Would anybody like to prove me wrong, by proving me
right? Shoot me an email at DillonR@fwgna.org. <b>The MSCGP is still
looking for volunteers!</b></p><p><u>Notes</u></p><p><b><span style="color: #783f04;">[1]</span></b> In yet another demonstration of the folly of legislating
common names, the official, AFS-sanctioned common name for <i>Pomacea
diffusa/bridgesii </i>is “spike-topped apple snail” <b><span style="color: #783f04;">[2]</span></b>. But I suspect that the generic term “apple
snail” has become too closely associated with invasive pests for the comfort of
the aquarium trade. For whatever reason, for quite a few years now the breeders and retailers have been marking “mystery snails”
on their aquaria of <i>Pomacea diffusa</i>. And
if that’s what it says on your sales receipt, that’s what it is when you get
home.</p><p><b><span style="color: #783f04;">[2]</span></b> Turgeon, D.D., J.F. Quinn, A.E. Bogan, E.V. Coan, F.G.
Hochberg, W.G. Lyons, P.M. Mikkelson, R.J. Neves, C.F.E. Roper, G. Rosenberg,
B. Roth, A. Scheltema, F.G. Thompson, M. Vecchione, and G.D. Williams (1998)
Common and scientific names of aquatic invertebrates from the United States and
Canada: Mollusks (second edition), American Fisheries Society Special
Publication 26, Bethesda, Maryland, 526 pp.</p><p><b><span style="color: #783f04;">[3] </span></b> I am quoting the
“late 1960s” domestication date for <i>P. diffusa</i> from the 1996 book by Perera & Walls,
page 36. Whether all eight color
varieties were available at that early date, I do not know. All varieties were certainly on the market by 1996, as
evidenced by their photos in:</p><p></p><ul style="text-align: left;"><li>Perera, G. and J.G. Walls (1996) Apple Snails in The
Aquarium. T.F.H. Publications, Neptune
City, NJ</li></ul><p></p><p><b><span style="color: #783f04;">[4]</span></b> Rawlings, T.A., K. A. Hayes, R. H. Cowie, and T. M.
Collins (2007) The identity,
distribution, and impacts of non-native apple snails in the continental United
States. BMC Evolutionary Biology 7: 97</p><p><b><span style="color: #783f04;">[5]</span></b> Blume, W. (1957) Eine bis heute unbekannte Unterart von<i>
Pomacea bridgesii</i> Rve. Opuscula
Zoologica 1: 1 – 2.</p><p><b><span style="color: #783f04;">[6]</span></b> We have directed at least ten or twelve posts on the
blog to invasive apple snails of the <i>P. canaliculata/maculata</i> type over the
last 20 years. For an entry into their
extensive literature, see:</p><div><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>REVIEW: Global Advances in Apple Snails [<a href="https://fwgna.blogspot.com/2010/02/review-global-advances-in-apple-snails.html" target="_blank">24May07</a>]</li><li>Two dispatches from the Pomacea front [<a href="https://fwgna.blogspot.com/2008/08/two-dispatches-from-pomacea-front.html" target="_blank">14Aug08</a>]</li><li>Pomacea news [<a href="https://fwgna.blogspot.com/2013/07/pomacea-news.html" target="_blank">25July13</a>]</li><li>Invasive species updates [<a href="https://fwgna.blogspot.com/2018/06/invasive-species-updates.html" target="_blank">13June18</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[7] </span></b>Actually, we have documented two complementing albinism
loci in our own favorite experimental animal, <i>Physa acuta</i>. See:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Albinism and sex allocation in Physa [<a href="https://fwgna.blogspot.com/2018/11/albinism-and-sex-allocation-in-physa.html" target="_blank">2Nov18</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Yusa, Y. (2004) Inheritance of colour polymorphism and
the pattern of sperm competition in the apple snail <i>Pomacea canaliculata</i>
(Gastropoda: Ampullariidae). Journal of Molluscan Studies 70: 43 – 48.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9] </span></b>Dillon, R. T.
(1998-99) The inheritance of
golden, a shell color variant of <i>Marisa cornuarietis</i>. Malacological Review
31/32: 155-157. [<a href="https://www.fwgna.org/dillonr/dillon98.pdf" target="_blank">PDF</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Cain, A.J., P.M. Sheppard, and J.M.B. King (1968) The
genetics of some morphs and varieties of <i>Cepaea nemoralis</i> (L). Philosophical Transactions of the Royal
Society B 253: 383 – 396. For more, see</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>King Arthur’s Lesson [<a href="https://fwgna.blogspot.com/2021/09/intrapopulation-gene-flow-king-arthurs.html" target="_blank">7Sept21</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> In 2005 Stijn
Ghesquiere added a “Genetics” page to his world-renowned <a href="http://applesnail.net">applesnail.net</a>
website, without attribution, featuring a three-locus, eight phenotype
Mendelian model very clearly developed and demonstrated.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> In addition to the <i>Marisa</i> I reared for my 1999 paper
<b><span style="color: #783f04;">[9]</span></b>, I also had one extended experience with <i>Pleurocera proxima</i> <b><span style="color: #783f04;">[13]</span></b>, which was
a huge pain in the ass. I know, however,
that I’m exaggerating about the “thousands of square feet” estimate up above. But give it to me – I’m trying to avoid an
argument with my wife here.</p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> Dillon, R.T. (1986) Inheritance of isozyme phenotype at
three loci in the freshwater snail, <i>Goniobasis proxima</i>: Mother-offspring
analysis and an artificial introduction. Biochemical Genetics 24: 281-290. [<a href="https://www.fwgna.org/dillonr/dillon1986.pdf" target="_blank">PDF</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Here’s my entire series on freshwater gastropods in the
home aquarium:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>What’s Out There? [<a href="https://fwgna.blogspot.com/2017/10/whats-out-there.html" target="_blank">9Oct17</a>]</li><li>Loved To Death? [<a href="https://fwgna.blogspot.com/2017/11/loved-to-death.html" target="_blank">6Nov17</a>]</li><li>Pet Shop Malacology [<a href="https://fwgna.blogspot.com/2017/12/pet-shop-malacology.html" target="_blank">21Dec17</a>]</li><li>Snails By Mail [<a href="https://fwgna.blogspot.com/2018/01/snails-by-mail.html" target="_blank">24Jan18</a>]</li><li>Freshwater Gastropods and Social Media [<a href="https://fwgna.blogspot.com/2018/02/freshwater-gastropods-and-social-media.html" target="_blank">14Feb17</a>]</li><li>Psst, Buddy! Wanna
Buy An Apple Snail? [<a href="https://fwgna.blogspot.com/2018/03/psst-buddy-wanna-buy-apple-snail.html" target="_blank">16Mar18</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><span style="color: #783f04; font-weight: bold;">[15]</span><span> Here's a funny demonstration of how unlearned I am in the ways of social media. In my original essay of 6June23 I used the verb "ghosting" here, to describe reading FB posts without commenting or participating in any way. On 8June23 my MSCGP colleague "Dylan" sent me an email correcting my verb choice to "lurking."</span></p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> Dillon, R. T., Jr. (2018) Welcome to the mystery snail
color genetics project! FWGNA Circular
7: 1 - 13. [<a href="https://www.fwgna.org/dillonr/MSCGP/mscgp.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[17] </span></b>The USGS <a href="https://nas.er.usgs.gov/" target="_blank">Nonindigineous aquatic species database</a> lists
42 records of <i>P. bridgesii/diffusa</i>, as compared to 2,948 records for “<i>Pomacea cf.
canaliculata/maculata</i>.”</p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> Here is Bill’s obituary: <a href="https://www.dignitymemorial.com/obituaries/jacksonville-fl/william-frank-10932042" target="_blank">William Michael Frank</a> (18Sep47
– 16Sept22)</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> In addition to <i>Pomacea diffusa</i>, the "ditches" along Jacksonville's Beach Blvd are inhabited by <i><a href="https://www.fwgna.org/species/ampullariidae/p_paludosa.html" target="_blank">Pomacea paludosa</a></i>, <a href="https://www.fwgna.org/species/thiaridae/m_tuberculata.html" target="_blank"><i>Melanoides tuberculata</i></a>, and <a href="https://www.fwgna.org/species/ancylidae/h_excentricus.html" target="_blank"><i>Hebetancylus excentricus</i></a>.</p></div>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-89763043944951268062023-05-09T14:03:00.011-04:002023-11-21T10:40:53.026-05:00Testing the Periwinkle Hypothesis<p><span style="font-size: xx-small;">Editor’s Notes – This essay is the second half of a two part
series on the systematics of the pleurocerid genus <i>Leptoxis</i>. We recommend that you familiarize yourself
with last month’s post [<a href="https://fwgna.blogspot.com/2023/04/growing-up-with-periwinkles.html" target="_blank">6Apr23</a>] before proceeding. </span></p><p><span style="font-size: xx-small;">This essay was <span style="font-family: times;">subsequently published as: Dillon, R.T., Jr. (2023b) Testing the Periwinkle Hypothesis. Pp 101 – 110 <b>in </b>The Freshwater Gastropods of
North America Volume 6, <i>Yankees at The Gap, and Other Essay</i>s. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></span></p><p>I first met Nathan Whelan, that brash young star of find ‘em
and grind ‘em malacology, at the Louisville meeting of the FMCS in April of 2011 <b><span style="color: #783f04;">[1]</span></b>.
He was bubbling with excitement about his dissertation research at the
University of Alabama, “the first phylogenetic study of <i>Leptoxis</i> to have
complete ingroup and adequate outgroup sampling.” Nathan’s 157-page dissertation, which
included chapters on egg laying behavior and nuclear copies of mitochondrial genes
(NUMTs), in addition to an extraordinarily ambitious molecular phylogeny, was published in 2013 <b><span style="color: #783f04;">[2]</span></b>.</p><p>Nathan analyzed N = 207 individual snails, focusing on 154
<i>Leptoxis</i> sampled from 39 populations of 13 nominal species, to which he added a
very large number of outgroups: 23 <i>Pleurocera/Elimia</i>, 20 Lithasia, 4 <i>Juga</i>, an
<i>Io</i> sample fished from Genbank, 2 <i>Cleopatra</i> from Zambia, and 3 “undescribed
pleurocerids” from the Collins River for which he would not hazard even a
genus.</p><p>He sequenced two nuclear genes (Histone H3 and 28S rRNA) and
two mitochondrial genes (16sRNA and CO1) for his big sample, and immediately
discovered 28 cases of mitochondrial superheterogeneity, recalling the
phenomenon my coworkers and I reported in 2009 <b><span style="color: #783f04;">[3]</span></b>. These highly divergent sequences he
attributed to NUMTs, an hypothesis which his subsequent research did not
confirm <b><span style="color: #783f04;">[4]</span></b>. Soldiering on undaunted, he
excluded 23 individual <i>Leptoxis</i> and 5 individual <i>Lithasia</i> from further
analysis, paring his total sample size down to N = 179.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCYMqEe9beR0nO13U5pK62xL1DtbTsLbVS87MGFSNHjOHwOJCuG-UtDBYFpCcXJ7EmIpFxzv5Ncs3jN_uZV8jari_d6LadhGS7wdvqB5QgQ3ostyFAn-9FJ7eZjmelH5UxGERRPDmolIsQeS1iOxSofT7c_r31o3iljfEq3rZu0nfTAseuRHP9Cp_0iA/s2911/Whelan2013-tree.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2911" data-original-width="1787" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCYMqEe9beR0nO13U5pK62xL1DtbTsLbVS87MGFSNHjOHwOJCuG-UtDBYFpCcXJ7EmIpFxzv5Ncs3jN_uZV8jari_d6LadhGS7wdvqB5QgQ3ostyFAn-9FJ7eZjmelH5UxGERRPDmolIsQeS1iOxSofT7c_r31o3iljfEq3rZu0nfTAseuRHP9Cp_0iA/w245-h400/Whelan2013-tree.jpg" width="245" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Whelan <b><span style="color: #783f04;">[1]</span></b> Fig 5.4, diagrammatic</span></td></tr></tbody></table>
<p class="MsoNormal">The figure above is a diagrammatic representation of
Nathan’s Figure 5.4, a Baysian tree based on concatenation of the four genes,
simplifying 179 branch tips <b><span style="color: #783f04;">[5]</span></b> down to eight boxes. I would suggest that you right-click on that figure and open a larger version in a new window, because we're going to discuss it in some detail. And if you’d like to see Nathan's original tree, with
all 179 tips unfolded and labelled, you are hereby invited to open [<a href="https://www.fwgna.org/downloads/Whelan2013-Fig5-4.jpg" target="_blank">this link</a>] in a third window as well <span style="color: #783f04;"><b>[6]</b></span>. And you'll need to max that third window up to life size. Nathan’s original Figure 5.4 was printed in
7-point font over two sequential 8.5 x 11 inch print pages, which I have pasted
together into a single 15 x 20 inch jpeg image for detailed examination. OK, are we ready to go forward?</p><p class="MsoNormal">The box shown in dashed outline at the bottom of the diagrammatic representation symbolizes 26% of the foliage of the tree, a total of 47 sequences,
including all the <i>Pleurocera/Elimia</i>, all the <i>Lithasia</i>, the <i>Io</i> and the
unidentified. Mingled in amongst the branches bearing all those taxa are the
sequences from three species of<i> Leptoxis</i>: <i>L. compacta</i> (5), <i>L. plicata</i> (2) and
<i>L. arkansensis</i> (4). This is the
phenomenon for which Nathan subsequently<b><span style="color: #783f04;"> [7]</span></b> coined the term, “prodigious
polyphyly” implying that results such as these bear some relationship to the
evolutionary relationships among the pleurocerid populations from which they
were drawn.</p><p class="MsoNormal">But gene trees are dependent variables, not independent
variables. Although they might certainly cast light on an hypothesis, they cannot
be used to construct an hypothesis. And
since I personally do not have enough research experience with <i>Leptoxis
compacta</i>, <i>L. plicata</i>, or <i>L. arkansensis</i> to have formed an hypothesis regarding
their evolutionary relationships <b><span style="color: #783f04;">[8]</span></b>, let’s trim the lower quarter of Nathan’s
tree off, and set those data aside. One
day we may be able to interpret them.
But today is not that day.</p><p class="MsoNormal">Now moving forward with the 74% of Nathan’s tree for which,
over 50 years of experience, I have developed an expectation. From top to
bottom, six results present themselves for discussion.</p><p class="MsoNormal">First, Nathan’s results support the 1998 hypothesis of
Dillon & Lydeard<b><span style="color: #783f04;"> [9]</span></b> that <b>the <i>Leptoxis</i> of the Alabama/Coosa system are
conspecific</b>, <i>Leptoxis picta</i> (Conrad 1834) being the oldest available name. The nomina <i>ampla</i> (Anthony 1855), <i>foremani</i> (Lea
1843), and <i>taeniata</i> (Conrad 1834), are all junior synonyms of <i>picta</i>.</p><p class="MsoNormal">Second, Nathan’s results support the hypothesis of Dillon
& Robinson <b><span style="color: #783f04;">[3]</span></b> that populations previously identified as <b><i>Leptoxis dilatata</i>
in the New/Greenbrier/Kanawha are trans-Appalachian <i><a href="https://www.fwgna.org/species/pleuroceridae/l_carinata.html" target="_blank">Leptoxis carinata</a></i>.</b></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnARqtLFUkg_08DcMoTkPl9PkMJ2PqPrHtIy_lrtdOdsEXKi7ffY52UFo3bnhQ0mfxvsNpPvX1hbW3Shuy7nA_Wsr7rPY5dOwwE4BV2j6iqQ2j4Gol3PZdopbZ5trJwY4iRB6XRDe299FB7fN-6drYM_1KPuVVa1NdsOUMFowUcKQS9saSdtICWFog_Q/s2141/L_carinata_eggs.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1605" data-original-width="2141" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnARqtLFUkg_08DcMoTkPl9PkMJ2PqPrHtIy_lrtdOdsEXKi7ffY52UFo3bnhQ0mfxvsNpPvX1hbW3Shuy7nA_Wsr7rPY5dOwwE4BV2j6iqQ2j4Gol3PZdopbZ5trJwY4iRB6XRDe299FB7fN-6drYM_1KPuVVa1NdsOUMFowUcKQS9saSdtICWFog_Q/w320-h240/L_carinata_eggs.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Leptoxis carinata</i> eggs</span></td></tr></tbody></table><p class="MsoNormal">And third, Nathan’s results support the hypothesis of Dillon
& Ahlstedt <b><span style="color: #783f04;">[10]</span></b> that <i><a href="https://www.fwgna.org/species/pleuroceridae/l_crassa.html" target="_blank">Leptoxis crassa</a></i> is closely related to, but specifically
distinct from, <i>Leptoxis praerosa</i>.
Reproductive isolation seems to have arisen in an East Tennessee
population of <i>L. praerosa</i>, rather than in Middle Tennessee, North Alabama, or
elsewhere <b><span style="color: #783f04;">[11]</span></b>. The subsequent level of
divergence does not seem to be of the magnitude of a subgenus, much less a
genus. The longstanding hypothesis that
large-bodied, heavily shelled pleurocerid populations described as <i>Melania
crassa</i> (Haldeman) or <i>Melania anthonyi </i>(Redfield) might be set aside in a unique
genus “<i>Eurycaelon</i>” or <b>“<i>Athearnia</i>” is not supported</b>.</p><p class="MsoNormal">Fourth. Nathan’s gene
tree depicts 8 populations of <i><a href="https://www.fwgna.org/species/pleuroceridae/l_praerosa.html" target="_blank">Leptoxis praerosa</a></i> sampled from East Tennessee
(four Clinch, one Powell, two Holston, one Nolichucky, comprising 14
individuals in total) as distinct from 9 populations (22 individuals) sampled
from elsewhere throughout the remainder of the range. Nathan suggested that this phenomenon might
reflect speciation, going so far as to nominate <i>subglobosa</i> (Say 1825) as a
possible name for the East Tennessee populations.</p><p class="MsoNormal">There is no evidence of sympatry between the eight <i>L.
praerosa</i> populations in Block 4 and the other nine populations in Block 5,
however. Such a phenomenon is just as
easily explained by geographic isolation as by reproductive isolation. Walden Ridge, constituting the eastern
escarpment of the Cumberland Plateau as it slashes diagonally through Tennessee
to Chattanooga, has long been recognized as an important biogeographic boundary
separating the aquatic faunas of East and Middle Tennessee, and cannot be ruled
out as a causative agent for the genetic discontinuity apparent between Block 4
and Block 5 above.</p><p class="MsoNormal">Fifth. Subsumed among
the nine populations in the main <i>Leptoxis praerosa</i> Block 5 were two populations
Nathan identified as <i><a href="https://www.fwgna.org/species/pleuroceridae/l_praerosa_umbilicata.html" target="_blank">Leptoxis umbilicata</a></i> – one from the East Fork Stones River
(5 individuals) and a second from Smith Fork of the Caney/Collins (3
individuals). There is no evidence of
any genetic divergence between these two populations and <i>Leptoxis praerosa</i>
sampled more broadly.</p><p class="MsoNormal">Indeed, our field surveys conducted throughout the
Tennessee/Cumberland catchment have confirmed populations of otherwise typical
<i>L. praerosa </i>bearing openly-umbilicate shells in the Stones River
subdrainage as well as in the Red River subdrainage (NW of Nashville) and
(sporadically) in the Elk.
Intrapopulation variation such as that depicted from a tributary of the Red River below,
together with the genetic data of Whelan, suggest that <b><i>L. umbilicata</i> (Wetherby
1876) be lowered to subspecific status <span style="color: #783f04;">[12]</span> under <i>Leptoxis praerosa.</i></b></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSj2qtnzyzIxdgDoEiSYlc4SOtmUBNQuRccsO0QQxw5NCOvsr5FD4AMMhZkgig61g96vDqgjqVSn848dhme_SFI5y2vmmj04zfpyLEBwUtGp_4U8eSK6v2HBw6tDnzZVBU7-TiANhCJWFMy5x1A-rJzjwErRc2xd1tMfWOfAYd6f0ts3q7ZfSXj8KVYA/s1344/L_praerosa-umbilicus-comparison.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="480" data-original-width="1344" height="114" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSj2qtnzyzIxdgDoEiSYlc4SOtmUBNQuRccsO0QQxw5NCOvsr5FD4AMMhZkgig61g96vDqgjqVSn848dhme_SFI5y2vmmj04zfpyLEBwUtGp_4U8eSK6v2HBw6tDnzZVBU7-TiANhCJWFMy5x1A-rJzjwErRc2xd1tMfWOfAYd6f0ts3q7ZfSXj8KVYA/s320/L_praerosa-umbilicus-comparison.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><i>Leptoxis praerosa umbilicata</i></td></tr></tbody></table><p class="MsoNormal">And sixth, and most interestingly. Nathan identified a set of 7 populations (21
individuals) from all around East Tennessee and North Alabama, in the Holston,
Hiwassee, Nolichucky, Sequatchie, Paint Rock and elsewhere, as “<i>Leptoxis
virgata</i>.” That subset of 7 populations
seems to bear a distinct mitochondrial haplotype, differing by roughly 0.8
mystery units of divergence <b><span style="color: #783f04;">[13] </span></b>from his 8 + 9 = 17 populations of <i>L. praerosa</i>. These 7 “<i>virgata</i>” populations seem effectively sympatric with <i>praerosa</i> populations over their entire range,
collectable side-by-side in the Nolichucky River at the SR340 bridge, Greene
County, TN.</p><p class="MsoNormal">The molecular distinction between <i>L. praerosa</i> and “<i>L.
virgata</i>” seems to be entirely mitochondrial.
Although Nathan included nuclear 28S and H3 data in his concatenated
Fig 5.4 tree, the separate trees he figured for the two nuclear genes individually did not seem to resolve <i>L. "virgata"</i> from the greater <i>Leptoxis
</i>background. The <i>praerosa/”virgata”</i>
distinction does, however, seem to include a morphological component. Nathan stated that “the shells of these
species are slightly different” but did not elaborate. You can be the judge from his Figure 4.5
below.</p><p class="MsoNormal">Nathan’s mitochondrial data plus the demonstrated sympatry
plus the (putative) shell morphological differences all combine to suggest that<b>
a pair of cryptic <i>Leptoxis</i> species co-occur in the rivers of East
Tennessee. </b> And since the range of the
more widespread (17-population) species extends north and west to include the
Falls of The Ohio, the best identification for the 17-population species must
be <i>Leptoxis praerosa</i>. Nathan’s
identification of the 7-population species as “<i>Leptoxis virgata</i>” is, however,
premature.</p><p class="MsoNormal">Before signing off on his dissertation, Nathan’s advisor
should have sent him back to the Nolichucky River at the SR340 bridge to do the
job right. Nathan should have been
instructed to collect a big, fresh sample of <i>Leptoxis</i>, paying close attention
to microhabitat, photograph them all, and measure their shells
thoroughly. Then he should have
sequenced them, and sorted them into two piles according to mtDNA haplotype. And then he should have cracked open a can of geometric morphometrics, or maybe an old-fashioned cigar box of discriminant function analysis, or maybe an even older-fashioned bivariate
statistical analysis, to see if any difference in the morphology of those two piles
of <i>Leptoxis</i> shells could be confirmed.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEir5dwuINRG2c0cDayx_OzjWqNppLTAsKsArOwm5OLF6uJmHq_YYg8PMQpRISrSA5s2DWD-72Yh9DugRcFvS5tkSGDmJ-VxnWKV7SA1mvVBOEex4cSUAU23OnMQ5X10E8F-ikKoVjLSw9V95qjvsTrv6-yKGa-mCJXFfOtjU98lAYHYwfLVB0JZ8XKl9Q/s967/Whelan-2013-Fig4-5.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="617" data-original-width="967" height="204" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEir5dwuINRG2c0cDayx_OzjWqNppLTAsKsArOwm5OLF6uJmHq_YYg8PMQpRISrSA5s2DWD-72Yh9DugRcFvS5tkSGDmJ-VxnWKV7SA1mvVBOEex4cSUAU23OnMQ5X10E8F-ikKoVjLSw9V95qjvsTrv6-yKGa-mCJXFfOtjU98lAYHYwfLVB0JZ8XKl9Q/s320/Whelan-2013-Fig4-5.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Whelan <b><span style="color: #783f04;">[2]</span></b> Fig 4.5, modified</span></td></tr></tbody></table><p class="MsoNormal">In the Pleuroceridae, species are defined by shell morphology. So if Nathan had indeed been able to detect some shell
morphological difference correlated with the mtDNA sequence divergence at the SR340 bridge, he
should then have gone back into the national collections and conducted a
similar morphological analysis on all the type specimens of all the <i>Leptoxis</i>
available, or (in any case) their images as reproduced in their descriptions,
and tried to find a match.</p><p class="MsoNormal">If, however, no shell morphological difference is detectable at the SR340 bridge, the pair of species may be judged true siblings. Then again, <i>Leptoxis praerosa</i> is (by definition) the name for
the more widespread. For the
less-widespread, perhaps the best course of action, only at this point, would have been to find a good-fitting junior synonym of <i>L. praerosa</i> to resurrect. Perhaps <i>virgata</i> (Lea 1841) is that synonym
<b><span style="color: #783f04;">[14]</span></b>. My nominee would be <i>subglobosa</i>
(Say 1825). But in no case and at no
time in this entire process are any additional newly-described pleurocerid nomina wanted on the
floor of the Augean Stables <b><span style="color: #783f04;">[15]</span></b>. I think Nathan and I are
together on that.</p><p class="MsoNormal">Alas, none of the above happened in 2013. If I were 20 years younger, the study as I have outlined it would have taken place in 2014 – 2015, using allozyme markers, which
are much more powerful than sequence data, but alas again, I am not. So, if any of you bright young students out
there are shopping for a research project, I’ve got a great one all laid
out for you on the banks of the Nolichucky. In fact, I’ve already got the
manuscript written for you, like a malacological ChatGPT.</p><p class="MsoNormal">Go back and re-read the series of three essays I posted in
the fall of 2016 on the cryptic <i>Pleurocera</i> of Maryville <b><span style="color: #783f04;">[16]</span></b>. You have my permission to copy and paste all that text into a fresh
manuscript, substitute <i>Leptoxis</i> for <i>Pleurocera</i> and Nolichucky River for Pistol
Creek, submit to Science or Nature, and call a press conference. Your next big NSF grant is assured, your
tenured professorship awaits.</p><p class="MsoNormal"><br /></p><p class="MsoNormal"><u>Notes</u>:</p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> In the original version of this essay, posted Tuesday afternoon 9May23, I stated that I first met Nathan in July of 2011 at the AMS. Nathan corrected me in an extensive comment posted shortly thereafter. His original 9May comment was subsequently deleted by Google, however, possibly because of some of the inflamatory language it included. So I resurrected his comment from the blogspot archives, emailed it back to Nathan, and he cleaned it up, and re-posted it on 11May. Look way down below.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2] </span></b>Whelan, Nathan V. (2013)
Conservation, life history and systematics of <i>Leptoxis</i> Rafinesque 1819
(Gastropoda: Cerithioidea: Pleuroceridae).
PhD Dissertation, University of Alabama, Tuscaloosa. 179 pp.</p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Dillon, R T. and
J. D. Robinson (2009) The snails the
dinosaurs saw: Are the pleurocerid populations of the Older Appalachians a
relict of the Paleozoic Era? Journal of
the North American Benthological Society 28: 1 - 11. [<a href="https://www.fwgna.org/dillonr/DillonRobinsonJNABS.pdf" target="_blank">pdf</a>] To review the state of our knowledge at that
(relatively early) stage in our understanding of the phenomenon we subsequently
termed “mitochondrial superheterogeneity,” see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The snails the dinosaurs saw [<a href="https://fwgna.blogspot.com/2009/03/snails-dinosaurs-saw.html" target="_blank">16Mar09</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[4] </span></b>Whelan, N.V. & E. E. Strong (2016) Morphology, molecules and taxonomy: extreme
incongruence in pleurocerids (Gastropoda, Cerithiodea, Pleuroceridae).
Zoologica Scripta 45: 62 – 87. To review the state of
our understanding of mitochondrial superheterogeneity at this (much improved)
state see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Mitochondrial superheterogeneity: What we know [<a href="https://fwgna.blogspot.com/2016/03/mitochondrial-superheterogeneity-what.html" target="_blank">15Mar16</a>]</li><li>Mitochondrial superheterogeneity: What if means [<a href="https://fwgna.blogspot.com/2016/04/mitochondrial-superheterogeneity-what.html" target="_blank">6Apr16</a>]</li><li>Mitochondrial superheterogeneity and speciation [<a href="https://fwgna.blogspot.com/2016/05/mitochondrial-superheterogeneity-and.html" target="_blank">3May16</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[5] </span></b>There is some discrepancy between the number of branch
tips depicted in Nathan’s Figure 5.4 and the number of samples as listed in his
Table 5.2, possibly due to duplicate sequences.
The sample sizes shown in my diagrammatic representation come from the
Table, not the Figure.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6] </span></b>Here is Nathan Whelan’s (2013) Figure 5.4:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Baysian phylogram inferred with the concatenated dataset with <i>Cleopatra</i> dropped for visualization purposes. [<a href="https://www.fwgna.org/downloads/Whelan2013-Fig5-4.jpg" target="_blank">jpg</a>] Numbers in front of nodes are posterior probabilities for each node. Scale bar meaningless.</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Whelan, N. V., P.D. Johnson, J.T. Garner, N.L. Garrison,
& E.E. Strong (2022) Prodigious polyphyly in Pleuroceridae (Gastropoda:
Cerithioidea). Bulletin of the SSB 1(2):
8419.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8] </span></b>I do have an hypothesis or two about the origin of
“prodigious paraphyly,” however.
Nathan’s Table 5.2, providing the sampling details for the 207
individual snails sequenced for his study, lists 63 populations, 31 of which
had sample sizes of 1 – 2 and 32 had sample sizes 3 – 6. Of the latter 32, 13 demonstrated
superheterogeneity ranging from 1 – 3.
Given such a background sampling distribution, it seems likely to me
that at least one or two populations of N = 5 (e.g., <i>L. compacta</i>) might be 100%
superheterogeneous, pushing <i>L. compacta</i> (for example) entirely off the <i>Leptoxis</i>
branches of Nathan’s tree.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9] </span></b>Dillon, R.T., and C. Lydeard (1998) Divergence among
Mobile Basin populations of the pleurocerid snail genus, <i>Leptoxis</i>, estimated by
allozyme electrophoresis. Malacologia.
39: 111-119. [<a href="https://www.fwgna.org/dillonr/dillon&lydeard98.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[10] </span></b>Dillon, R. T., and S. A. Ahlstedt (1997) Verification of
the specific status of the endangered Anthony's River Snail, <i>Athearnia
anthonyi</i>, using allozyme electrophoresis. The Nautilus 110: 97 - 101. [<a href="https://www.fwgna.org/dillonr/dillon&ahlstedt.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> The speciation of <i>Leptoxis crassa</i> from a <i>Leptoxis
praerosa</i> population rendered <i>L. praerosa</i> paraphyletic. A cladist is any biologist who, upon first
hearing the definition of the word, “paraphyly,” didn’t immediately react, “So,
what?”</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> Subspecies are populations of the same species in
different geographic locations, with one or more distinguishing traits. For more, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>What is a subspecies? [<a href="https://fwgna.blogspot.com/2014/02/what-is-subspecies.html" target="_blank">4Feb14</a>]</li><li>What subspecies are not [<a href="https://fwgna.blogspot.com/2014/03/what-subspecies-are-not.html" target="_blank">5Mar14</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> As fastidious as he is about the nodes of his gene
trees, Nathan is cavalier with the branches.
His Chapter 5 phylogenetic studies include no data on percent sequence
divergence whatsoever. And (alas) I
could not find any of his 2013 sequence data in GenBank. But the scale bar at the bottom of his Figure
5.4 is marked “0.4,” so eyeballing from that, it appears that the sequence
divergence between his <i>L. virgata</i> cluster and his larger <i>L. praerosa</i> cluster is
approximately 0.8 somethings.</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Isaac Lea described <i>Melania virgata</i> in 1841 from a
single 0.3 inch (=7.6 mm) shell sent to him by Dr. Troost from
“Tennessee.” Tryon demoted<i> virgata</i> to a
“variety” of <i>Anculosa subglobosa</i>. But to my eye, and to that of Calvin Goodrich, Lea’s little figure of the shell, showing a relatively small aperture (“about
half the length of the shell”) seems to depict a youngish <i>Leptoxis carinata</i>, a
population of which has indeed jumped over the low hills from the New River
into the Holston of Virginia, and could indeed have been picked up by Troost
downstream in Tennessee. So Goodrich
shifted <i>virgata</i> over to the genus <i>Nitocris</i> with <i>carinata</i> as he grouped <i>Anculosa subglobosa</i> together with <i>A. praerosa</i>.
Burch followed Goodrich biologically, although not taxonomically,
substituting <i>Leptoxis</i> for <i>Anculosa</i>, grouping <i>virgata</i> with <i>carinata </i>in the
subgenus <i>Mudalia</i>, leaving <i>praerosa</i> in the typical subgenus. Bottom line is that in choosing to identify a
putative species cryptic under praerosa as “<i>Leptoxis virgata</i>,” Nathan is
following Tryon, and disagreeing with Goodrich, Burch, and Rob Dillon, all
three of us together. Brash.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> This is an oblique reference to a very specialized, and
hence very useful, reference work to the taxonomy of the Pleuroceridae:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Graf, D. L. (2001)
The cleansing of the Augean stables.
Walkerana 12(27): 1 - 124.</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> My three-part series on the rediscovery of <i>Pleurocera
gabbiana</i>, cryptic under <i>P. simplex</i> in East Tennessee, was published
both informally on this blog and more formally, in the FMCS Newsletter. See:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>[<a href="https://fwgna.blogspot.com/2016/09/the-cryptic-pleurocera-of-maryville.html" target="_blank">13Sept16</a>] Dillon, R. T. (2016) Two reproductively isolated
populations cryptic under <i>Pleurocera simplex</i> (Say, 1825) inhabiting Pistol
Creek in Maryville, Tennessee.<span style="mso-spacerun: yes;">
</span>Ellipsaria 18(2): 15-16. [<a href="https://www.fwgna.org/dillonr/dillon-ellipsaria-18-2.pdf" target="_blank">pdf</a>]<span style="mso-spacerun: yes;"> </span></li><li>[<a href="https://fwgna.blogspot.com/2016/10/the-fat-simplex-of-maryville-matches.html" target="_blank">14Oct16</a>] Dillon, R. T. & J. D. Robinson (2016) The
identity of the "fat simplex" population inhabiting Pistol Creek in
Maryville, Tennessee.<span style="mso-spacerun: yes;"> </span>Ellipsaria 18(2):
16-18. [<a href="https://www.fwgna.org/dillonr/dillon&robinson-ellipsaria-18-2.pdf" target="_blank">pdf</a>] </li><li>[<a href="https://fwgna.blogspot.com/2016/11/one-goodrich-missed-skinny-simplex-of.html" target="_blank">14Nov16</a>] Dillon, R. T. (2016)<span style="mso-spacerun: yes;"> </span>Match of <i>Pleurocera gabbiana</i> (Lea, 1862) to
populations cryptic under <i>P. simplex</i> (Say, 1825).<span style="mso-spacerun: yes;"> </span>Ellipsaria 18(3): 10 - 12.<span style="mso-spacerun: yes;"> </span>[<a href="https://www.fwgna.org/dillonr/dillon-ellipsaria-18-3.pdf" target="_blank">pdf</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com11tag:blogger.com,1999:blog-1925453458905823877.post-37236185350166210502023-04-06T12:22:00.005-04:002023-11-21T10:31:14.531-05:00Growing up with periwinkles<p class="MsoNormal"><o:p></o:p></p><p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as:
Dillon, R.T., Jr. (2023b) Growing Up With Periwinkles. Pp 89 – 99 <b>in</b> The
Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other
Essays.</i> <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Back in 2014 I posted a reminiscence on this blog <b><span style="color: #783f04;">[1]</span></b> about
growing up a frustrated young malacologist in the little city of Waynesboro,
Virginia. From my house it was just a
couple hundred yards through old fields to the South River, a tributary of the
Shenandoah. And I wrote:</p><p></p><blockquote><span style="font-size: x-small;">“The rocks were (and still are) covered with little black
snails we called ‘periwinkles.’ I didn't collect them for the same reason I
didn't collect ants. They were
dirt-common, and (in retrospect) I think my collecting button only got pushed
when I saw something that seemed unusual, which periwinkles were not. And I knew for a fact that, just as was the
case with ants, I could not identify those periwinkles, even if I dug through
every "Mollusca" card in the University of Virginia Library catalog,
which I had.”</span></blockquote><p></p><p>I dropped the subject of “periwinkles” at that point of the
essay, in favor of another even more common and even more frustrating
freshwater snail, that of dirt-brown hue, <i>Physa</i>. So, this month we’ll pick at that
little-black periwinkle thread again and see what unravels behind it.</p><p>Because those periwinkles were the most conspicuous
gastropod of my youth. Further south up
the Great Valley of Virginia my father and I spent many lovely hours fishing in
the James River and tributaries such as the Cowpasture and the Jackson. And the next river heading south was the
Roanoke, where I had dozens of cousins, and the next river was the New River,
in whose bosom I wiled away four sweet, gauzy years of college. And in all of those river systems, in every
rapid or riffle big enough for a sun perch or a redeye bass, the rocks were
covered with little black periwinkles.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXqDVeNNfnNHsz7Z1QXf0NzFt8i7rQHZv9vKlqkeql8exp67yWFKNZoXKhXGHXrRt_HsoEyiscOv0wtOD4HpYsJdeeyNgT8xSqCjBo_udCoL7Ja9XqOj6wRSEpI7yzu0Hx46n0RebxnGB-ImA3G6RoEOz2h8MPCPjDmCSl5vGblpN8mopWKLyuX0Phaw/s2560/Back-Jackson-James.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2560" data-original-width="1920" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXqDVeNNfnNHsz7Z1QXf0NzFt8i7rQHZv9vKlqkeql8exp67yWFKNZoXKhXGHXrRt_HsoEyiscOv0wtOD4HpYsJdeeyNgT8xSqCjBo_udCoL7Ja9XqOj6wRSEpI7yzu0Hx46n0RebxnGB-ImA3G6RoEOz2h8MPCPjDmCSl5vGblpN8mopWKLyuX0Phaw/s320/Back-Jackson-James.jpg" width="240" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Jackson R, Va.</span></td></tr></tbody></table><p>It was only after my arrival at Virginia Tech in the fall of
1973 that I was finally able to identify “periwinkles,” poking through the
malacological journals, reading backward through the literature, discovering
the work of Calvin Goodrich <b><span style="color: #783f04;">[2]</span></b>.
<i><a href="https://www.fwgna.org/species/pleuroceridae/l_carinata.html" target="_blank">Nitocris carinata</a></i>! Authored by
the French zoologist Jean Guillaume Bruguière in 1792, <i>“Bulimus” carinatus</i> was
the second freshwater gastropod <b><span style="color: #783f04;">[3]</span></b> described from the continent of North
America, “<i>les eaux douces de la Virginie</i>” <b><span style="color: #783f04;">[4]</span></b>.
Goodrich gave its range as “New York to North Carolina.”</p><p>But almost immediately after I had solved the mystery of the
specific identity of the periwinkle, a fresh mystery presented itself. To what genus should the periwinkle be
assigned? Although Goodrich advocated
<i>Nitocris</i> (H. & A. Adams 1854), Dr. E. F. (Fred) Benfield, my undergraduate
advisor, preferred old Joe Morrison’s <b><span style="color: #783f04;">[5]</span></b> <i>Mudalia</i> (Haldeman 1840). Tryon <b><span style="color: #783f04;">[6] </span></b>and Walker <b><span style="color: #783f04;">[7]</span></b> preferred <i>Anculosa</i>
(Say 1821). And Juan Parodiz, who had
authored the best review of the systematics and distribution of periwinkles to that
date <b><span style="color: #783f04;">[8]</span></b>, made a case for <i>Leptoxis</i> (Rafinesque 1819), pushing <i>Mudalia</i>
underneath<i> Leptoxis</i> as a subgenus. It
turned out that I had stumbled into one of the most contentious issues in
American malacology.</p><p>There were actually two layers of controversy. The first was
whether Rafinesque had described his (1819) <i>Leptoxis </i>with sufficient clarity
that it might take precedence over Say’s (1821) <i>Anculosa</i>. And the second was whether either of two
subsequent names, <i>Mudalia</i> of Haldeman or <i>Nitocris</i> of H & A Adams, both
originally proposed as subgenera, might deserve elevation to the full genus
level. Iced over those layers of
controversy was the situation with a larger-bodied group that Tryon, Walker and
Goodrich all referred to as <i>Eurycaelon</i> (Lea, 1864), but which Joe Morrison
insisted was in error, for which he proposed the new name <i>Athearnia</i> in 1971,
more below. And then there was a funny
little sprinkle of walnuts on top about <i>Alleghenya</i>.</p><p>Who among my vast and diverse readership has ever heard of
Dr. Kenneth J. Boss? I didn’t think
so. Boss was a student of Bill Clench,
and heir to the curatorship of malacology at the MCZ Harvard. He had a quiet career, bless his heart. But in 1967 he and his mentor published a
little paper ignoring <i>Leptoxis</i>, discounting <i>Mudalia</i> and <i>Nitocris</i>, and proposing
to classify periwinkles in a new subgenus of <i>Anculosa</i> they called “<i>Alleghenya</i>”
<b><span style="color: #783f04;">[9]</span></b>.</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPrBGZTIIrXYVe0l4wgIa8v1wZBILyJBtb17X18vIo8wB72ztfqB41uvXaOROAjzg2pDM1qzB0_TaTgHeVKr5Kfj6G0oze7gNqSXuRLfCWN62rYdKA_DbPc6UBrNolWVLZOZavKSOI6erW99h7Uejni1qstgm6YqNt6svxx3O9LUUk4DZnUG2gu0dOFw/s1484/Parodiz-1956.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1484" data-original-width="1176" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgPrBGZTIIrXYVe0l4wgIa8v1wZBILyJBtb17X18vIo8wB72ztfqB41uvXaOROAjzg2pDM1qzB0_TaTgHeVKr5Kfj6G0oze7gNqSXuRLfCWN62rYdKA_DbPc6UBrNolWVLZOZavKSOI6erW99h7Uejni1qstgm6YqNt6svxx3O9LUUk4DZnUG2gu0dOFw/s320/Parodiz-1956.jpg" width="254" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>L. carinata</i> from Parodiz <b><span style="color: #783f04;">[8]</span></b></span></td></tr></tbody></table>I met Ken Boss in January of 1977, when I was interviewing prospective
graduate advisors. And I asked him what
the hell he was thinking with this <i>Alleghenya</i> thing, which was a pretty cheeky
way for a 21-year-old student to address a Harvard professor. And he admitted his mistake and apologized <b><span style="color: #783f04;">[10]</span></b>.<p></p><p>I ultimately chose <i>Mudalia</i> as the genus under which to file the
periwinkles I collected during the course of my undergraduate thesis research <b><span style="color: #783f04;">[11]</span></b>,
because that’s the name my faculty advisor preferred. But three years after I graduated, Jack Burch
<b><span style="color: #783f04;">[12]</span></b> brought the tablets down the mountain, and engraved upon them was <i>Leptoxis</i>
at the genus level, with <i>Mudalia</i> a subgenus beneath it. Burch didn’t offer any rationale, but neither
did God <b><span style="color: #783f04;">[13]</span></b>. And <i>Leptoxis</i> it has been, ever
since.</p><p>But here’s a fresh puzzle, now that we’ve identified those
periwinkles that covered the rocks in the South River of my youth as <i>Leptoxis
</i>(aka <i>Nitocris</i>, aka <i>Mudalia</i>) <i>carinata</i> (Brug 1792). When I left home for college, I drove south
up the Great Valley through the James River drainage, which was chock full of
<i>L. carinata</i>, and the Roanoke River drainage, which was chock full of <i>L.
carinata</i>, and then up the long grade to the New River Plateau. But for reasons unknown and unexplained,
Calvin Goodrich <b><span style="color: #783f04;">[14]</span></b> identified the periwinkles of the New River drainage as
<i>Nitocris</i> (aka <i>Leptoxis</i>, aka <i>Mudalia</i>) <i>dilatatus</i> (Conrad 1834), not <i>carinata</i>.</p><p>True, the vast herds of periwinkles covering the rocks in
the New River tributaries outside my dorm room window in Blacksburg bore shells
lacking that carination so often prominent on the shells borne by the herds of
periwinkles outside my bedroom window in Waynesboro. But by the time I was 20 years old I had been
kicking those little things off rocks for 15 years, all over the Commonwealth
of Virginia, and I knew how variable that little black shell could be.</p><p>And true, the New River drains west to the Ohio, while the
Shenandoah, James, and Roanoke drain east to the Atlantic. But even in my tender youth I was already
tremendously impressed by the extensive geographic ranges demonstrated by pleurocerid
snails. I didn’t understand it. Still don’t <b><span style="color: #783f04;">[15]</span></b>. But as Goodrich observed, <i>Leptoxis carinata</i>
is found in every Atlantic drainage from the Susquehanna way up in New York to
the Broad/Congaree way down in North Carolina, and on that scale the 10 mile climb
up I-81 leaving the Roanoke River Valley and entering the New River plateau doesn't amount to a hill of beans. And ditto
continuing back down the Blue Ridge on I-77 south from the New to the
Yadkin/Pee Dee. The little black
periwinkles swap <i>carinata-dilatata-carinata</i> over that 50 mile stretch, really?</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLMV6Z-OMUgf-HliC5CUIjHGEh2RGZz9f1x06f9WL51zHtxj7IN-avfEfg15E47nE1ura0kLVCDb3ikQQjawXk5sAB9IK9GrQtgDzme96TBnZjl7pMlYb55qxbZ2PcydUbQDqHyDBwH7nhDN1KYD7oICxYn9G_Dlu1qaWPtt49No-z4tdb_4wqajGk9Q/s1876/M-dilatata-1977.jpg" style="margin-left: auto; margin-right: auto;"><span style="font-size: x-small;"><img border="0" data-original-height="719" data-original-width="1876" height="123" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgLMV6Z-OMUgf-HliC5CUIjHGEh2RGZz9f1x06f9WL51zHtxj7IN-avfEfg15E47nE1ura0kLVCDb3ikQQjawXk5sAB9IK9GrQtgDzme96TBnZjl7pMlYb55qxbZ2PcydUbQDqHyDBwH7nhDN1KYD7oICxYn9G_Dlu1qaWPtt49No-z4tdb_4wqajGk9Q/s320/M-dilatata-1977.jpg" width="320" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">"<i>Mudalia dilatata</i>" from my ugrad thesis [<b><span style="color: #783f04;">11</span></b>]</span></td></tr></tbody></table>Moreover, by my undergraduate years I was already becoming
obsessed with another local pleurocerid, <i>Pleurocera</i> (aka <i>Goniobasis</i>, aka
<i>Elimia</i>) <i>proxima</i>, the range of which did extend across the Dan/Roanoke through
the New River into the Yadkin/Pee Dee, with no apparent interruption. Why should Goodrich distinguish the New River
<i>Leptoxis</i> with a unique name, “<i>Nitocris dilatata,</i>” while identifying all the
<i>Pleurocera</i> across the entire Roanoke-New-Pee Dee region as “<i><a href="https://www.fwgna.org/species/pleuroceridae/g_prox.html" target="_blank">Goniobasis proxima</a></i>?"<p></p><p>It took thirty years, but John Robinson and I ultimately
answered that question in 2009, with the survey of CO1 sequence divergence we
called “The Snails the Dinosaurs Saw <b><span style="color: #783f04;">[16].</span></b>”
Although the focus of that study was mitochondrial superheterogeneity
within populations, we did not neglect interpopulation divergence as well. Our pair of <i>carinata/dilatata </i>populations
from the Yadkin/New were more similar to each other than to their nominal
conspecifics in a <i>carinata/dilatata</i> pair sampled from the James/Greenbrier 150
km north. Conrad’s (1835) <i>dilatata</i> is a
junior synonym of Bruguiere’s (1792) <i>carinata</i>.</p><p>But back to the thread of my story. It was also during my undergraduate years at
Virginia Tech that I was first introduced to the second-oldest species of
<i>Leptoxis</i> in North America, Thomas Say’s <i>“Melania” praerosa</i>, described from the
Falls of the Ohio in 1821. The
introduction came in 1975, during the summer after my sophomore year, when I
was blessed to be offered a temporary job with the Tennessee Valley Authority
in Norris, and it was my new co-worker Steve Ahlstedt who did the honors. Interestingly, Steve called those little
snails “<i>Anculosa subglobosa</i>,” which was my first introduction to a specific
controversy almost as idiosyncratic as the controversy over the genus.</p><p>Thomas Say described “<i>Melania subglobosa</i>” from the North
Fork of the Holston River in 1825, and the species was considered distinct and
valid by all authors through the 19th and most of the 20th century, including by Tryon <b><span style="color: #783f04;">[6]</span></b> and Goodrich <b><span style="color: #783f04;">[14]</span></b>, both of whom assigned it to
<i>Anculosa</i>. But in 1980 Jack Burch <b><span style="color: #783f04;">[12]</span></b> synonymized <i>subglobosa</i> under Say’s
<i>praerosa</i> without explanation<b><span style="color: #783f04;"> [17] </span></b>or even comment. He simply wrote, in the caption of the figure printed on his page 157: “FIG. 480. <i>L. subglobosa</i> = <i>L. praerosa</i>.” And just like that, <i>Anculosa subglobosa</i> (Say 1825) was gone.</p><p>By whatever name, I found <i><a href="https://www.fwgna.org/species/pleuroceridae/l_praerosa.html" target="_blank">Leptoxis praerosa</a></i> populations
as widespread and dense in the rich headwaters of the Tennessee River to the
west of the New River as <i>L. carinata</i> were in the Yadkin/PeeDee to the South and
the Dan/Roanoke to the east.
Interestingly, <i>carinata</i> has apparently dispersed into the upper
Holston/Tennessee with <i>praerosa</i>, and <i>praerosa</i> seems to have spread into Walker
Creek of the New River with <i>carinata</i>, and in neither of these drainage systems
is any hybridization in evidence, to my eye, in any case.</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgcCKVvyaRBNO2Ee_XOFUl4I-yoHbjYepF2Fp0h1LR3McB8fmuFnlA0fwnLlEAZbjnOxeBENne7a2_13sSZAVM7Bn97Ja1xK1SW39Q4SZCuLdQPLkXWwjbC_fYUZB4kl88UvVRzvEK88s3lRaUGe1Xxcs7_VhxddAeZB-9RNx__wy7vqpeM0OuWxHDuA/s600/L_praerosa_Lukhaup.JPG" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="403" data-original-width="600" height="215" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgcCKVvyaRBNO2Ee_XOFUl4I-yoHbjYepF2Fp0h1LR3McB8fmuFnlA0fwnLlEAZbjnOxeBENne7a2_13sSZAVM7Bn97Ja1xK1SW39Q4SZCuLdQPLkXWwjbC_fYUZB4kl88UvVRzvEK88s3lRaUGe1Xxcs7_VhxddAeZB-9RNx__wy7vqpeM0OuWxHDuA/s320/L_praerosa_Lukhaup.JPG" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Leptoxis praerosa</i>, thanks to Chris Lukhaup</span></td></tr></tbody></table>The two species are easy to distinguish by the relative
sizes of their body whorls, <i>L. praerosa</i>’s being so large as almost to obscure
the apex entirely, smoothly rounded and entirely unsculptured, with no hint of
carination. They look like pebbles, with
a bit more mobility, but less personality.
It is perhaps their unmitigated plainness that has spared them the
metastasis of synonymy that has afflicted almost every other biological species
of pleurocerid snail in North America.
All across their eight-state range, Goodrich listed only nine synonyms
for <i>praerosa</i> and four for <i>subglobosa</i>, all of which are too obscure to mention.<p></p><p>Because populations are so widespread throughout the Ohio,
Cumberland, and Tennessee drainages, and because (up until recently) their
identity was uncontroversial, <i>Leptoxis praerosa</i> was an easy choice as a control
for two allozyme studies I published in the 1990s, one of <i><a href="https://www.fwgna.org/species/pleuroceridae/l_crassa.html" target="_blank">Leptoxis crassa</a></i> <b><span style="color: #783f04;">[18]</span></b>
and a second of the Alabama taxa <i>L. picta, L. ampla, L. plicata</i>, and <i>L.
taeniata</i> <b><span style="color: #783f04;">[19]</span></b>. In that former study,
Steve Ahlstedt and I confirmed reproductive isolation at four loci between
sympatric populations of <i>L. praerosa</i> and <i>L. crassa</i> co-occurring in the
Sequatchie River, about 10 miles west of Chattanooga.</p><p>Steve and I identified the population of big-bodied
pleurocerids we sampled from the Sequatchie as “<i>Athearnia anthonyi</i>.” That was the name Steve wrote on the
label in the bag of snails he shipped to me on dry ice, which I transferred to
my data sheets, anyway. In 1971 old Joe
Morrison proposed <i>Athearnia</i> as a genus to hold two nominal species of
large-bodied pleurocerids that Tryon, Walker and Goodrich had all previously
assigned to <i>Eurycaelon</i> (Lea 1864): <i>Melania crassa</i> Haldeman 1842 and <i>Melania
anthonyi</i> Redfield 1854 <b><span style="color: #783f04;">[20]</span></b>. Burch demoted
<i>Athearnia</i> to subgeneric rank under <i>Leptoxis</i> in 1980, and lowered <i>anthonyi</i> to
subspecific level under <i>crassa</i>. But in
1994 the US Fish & Wildlife listed “<i>Athearnia anthonyi</i>” as an endangered
species, declaring <i>A. crassa</i> extinct in the process <b><span style="color: #783f04;">[21]</span></b>, pretty much freezing
the 1971 science forever <b><span style="color: #783f04;">[22]</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrjASYVTUM7Vv525moISukmUbJ4m6QItuPs-yGc2M_UuUjhtEZ7assSUZ9lYyEFYwQS6jps6LTOPn6E9LvLTbRPthQ0Wkmaprcs6pGZtSISIVQPjgSW-c5U1ZTSm8zlBXKTqB6EuxLyCnHnDJlp3I4lTTV40SefM8jFoCWGJUK96F0dCoV4ZJT82w6kg/s2386/L_crassa.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1789" data-original-width="2386" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrjASYVTUM7Vv525moISukmUbJ4m6QItuPs-yGc2M_UuUjhtEZ7assSUZ9lYyEFYwQS6jps6LTOPn6E9LvLTbRPthQ0Wkmaprcs6pGZtSISIVQPjgSW-c5U1ZTSm8zlBXKTqB6EuxLyCnHnDJlp3I4lTTV40SefM8jFoCWGJUK96F0dCoV4ZJT82w6kg/s320/L_crassa.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Leptoxis crassa</i> in Limestone Ck.</span></td></tr></tbody></table><p>So shortly after Steve Ahlstedt and I published our paper on
<i>L. crassa</i>, Chuck Lydeard sent me a big batch of <i>Leptoxis</i> from the Mobile Basin
<b><span style="color: #783f04;">[19]</span></b>. I opened the cooler to find eight
populations of four nominal species: three of <i>L. ampla</i> from shoals of the
Cahaba River, two of <i>L. taeniata </i>from tributaries of the Coosa, two of <i>L.
plicata</i> from Locust Fork (of the Black Warrior) and one of <i>L. picta</i> from the
main Alabama River. The levels
of allozyme divergence among six of those eight populations turned out to be comparable to that demonstrated
by a set of three <i>L. praerosa</i> control populations I collected from Tennessee drainages
separated by similar distances. Our analysis suggested that <i>ampla, taeniata</i>, and <i>picta</i> were all conspecific,
<i>Leptoxis picta </i>(Conrad 1834) being the oldest name for the lot. The average allozyme divergence demonstrated
by the <i>L. plicata</i> populations of the Black Warrior system was consistent with
their status as a distinct biological species.</p><p>So if you had asked me ten years ago, I would have listed <b>six
valid species of Leptoxis in North America: carinata, praerosa, crassa, picta,
plicata,</b> and maybe that weirdo way out in the Ozarks, Leptoxis <b>arkansensis
</b>(Hinkley 1915), I have no reason to doubt.
That six-species hypothesis comes from over 60 years of field experience
with <i>Leptoxis</i> in the creeks, thousands of hours of laboratory research on the
genetics of pleurocerid populations, and an intimate familiarity with 200 years
of accumulated scientific literature. It
is science. It is a testable model of
the natural world. Next month, we test
it.</p><p><br /></p><p><u>Notes</u>:</p><p><b><span style="color: #783f04;">[1]</span></b> This was the first episode in what turned out to be a
five-part series on the evolution of our understanding of the North American
Physidae. If you’re curious about the
entire <i>Physa</i> story, the best approach might be to go to the final installment
[<a href="https://fwgna.blogspot.com/2018/12/to-identify-physa-2000.html" target="_blank">6Dec18</a>] and read backwards. Otherwise:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>To Identify a Physa, 1971 [<a href="https://fwgna.blogspot.com/2014/04/to-identify-physa-1971.html" target="_blank">8Apr14</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[2] </span></b>Goodrich, C. (1942) The Pleuroceridae of the Atlantic
coastal plain. Occasional Papers of the
Museum of Zoology, University of Michigan 456: 1 – 6. For an appreciation, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Legacy of Calvin Goodrich [<a href="https://fwgna.blogspot.com/2007/01/legacy-of-calvin-goodrich.html" target="_blank">23Jan07</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> To the German naturalist Johann Friedrich Gmelin goes the honor of describing
the first freshwater gastropod endemic to North America, <i>“Buccinum”
(Pleurocera) virginicum</i> in 1791.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Bruguière, Jean Guillaume (1792) Vermes ('worms') in
Daubenton's <i>Encyclopédie Méthodique</i>.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Morrison, J. P.
E. (1954) The relationships of Old and New World Melanians. Proc. U. S. Nat.
Mus. 103: 357- 394. For context, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Joe Morrison and the great Pleurocera controversy [<a href="https://fwgna.blogspot.com/2010/11/joe-morrison-and-great-pleurocera.html" target="_blank">10Nov10</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Tryon, G. W. (1873)
Land and Freshwater shells of North America Part IV, Strepomatidae. Smithsonian Miscellaneous Collections 253: 1
- 435. For a thumbnail biography, see down below in my Isaac Lea bio:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Isaac Lea Drives Me Nuts [<a href="https://fwgna.blogspot.com/2019/11/isaac-lea-drives-me-nuts.html" target="_blank">5Nov19</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[7] </span></b>Walker, B. (1918)
A synopsis of the classification of the freshwater Mollusca of North
America, North of Mexico, and a catalogue of the more recently described
species, with notes. Univ. Mich. Mus.
Zool. Misc. Publ. 6: 1 - 213. For an
appreciation, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Bryant Walker’s sense of fairness [<a href="https://fwgna.blogspot.com/2012/11/bryant-walkers-sense-of-fairness.html" target="_blank">9Nov12</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Parodiz, J. J. 1956.
Notes on the freshwater snail <i>Leptoxis (Mudalia) carinata</i>. Annals of the Carnegie Museum 33: 391 - 405.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> Clench, W.J. and K. J. Boss (1967) Freshwater Mollusca
from James River, Va., and a new name for <i>Mudalia</i> of authors. Nautilus 80: 99 – 102.</p><p class="MsoNormal"><b><span style="color: #783f04;">[10] </span></b>But Ken Boss was never going to win me as a graduate
student, in any case. George Davis had
greatly impressed me at the AMU meeting in the summer of 1976, and was a very
gracious host in Philadelphia, and I was hooked. Burch had the early lead, but by the winter
of 1976-77 had blown it</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Dillon, R. T., Jr. (1977) Factors in the distributional
ecology of upper New River mollusks (Va/NC).
Undergraduate Research Thesis, Virginia Tech, Blacksburg. 59 pp. [<a href="https://www.fwgna.org/dillonr/Dillon77.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> This is a difficult work to cite. J. B. Burch's North American Freshwater
Snails was published in three different ways.
It was initially commissioned as an identification manual by the US EPA
and published by the agency in 1982. It
was also serially published in the journal Walkerana (1980, 1982, 1988) and
finally as stand-alone volume in 1989 (Malacological Publications, Hamburg,
MI).</p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> Actually, He did, for numbers two and four only. But for the rationale of number two, at least, it is difficult to be thankful.</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Goodrich, C. 1940. The Pleuroceridae of the Ohio River
drainage system. Occas. Pprs. Mus. Zool.
Univ. Mich., 417: 1-21.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> Well, the older
I get, the more convinced I become that extensive pleurocerid ranges such as those
displayed by <i>Leptoxis carinata</i> and <i>Pleurocera proxima</i> are the product of great
age and extremely unlikely aerial dispersal events. See the “jetlagged wildebison model” here:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Mitochondrial superheterogeneity: What it means [<a href="https://fwgna.blogspot.com/2016/04/mitochondrial-superheterogeneity-what.html" target="_blank">6Apr16</a>]</li><li>Accelerating the snail’s pace, 2012 [<a href="https://fwgna.blogspot.com/2017/04/accelerating-snails-pace-2012.html" target="_blank">24Apr17</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> Dillon, R. T., Jr. and J. D. Robinson (2009) The snails the dinosaurs saw: Are the
pleurocerid populations of the Older Appalachians a relict of the Paleozoic
Era? Journal of the North American Benthological
Society 28: 1 - 11. (Rosemary Mackay
Award) [<a href="https://www.fwgna.org/dillonr/DillonRobinsonJNABS.pdf" target="_blank">pdf</a>] For more, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The snails the dinosaurs saw [<a href="https://fwgna.blogspot.com/2009/03/snails-dinosaurs-saw.html" target="_blank">16Mar09</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> The ultimate cause may have been sloppiness. There is a line space missing between Goodrich’s
treatment of <i>Anculosa praerosa</i> and his treatment of <i>Anculosa subglobosa</i> at the
bottom of page 20 in his 1940 paper, which pulls <i>subglobosa</i> up underneath Goodrich’s
list of nine <i>praerosa</i> synonyms. Is it possible that Burch thought Goodrich was listing <i>subglobosa</i> as a tenth?</p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> Dillon, R. T., and S. A. Ahlstedt (1997) Verification
of the specific status of the endangered Anthony's River Snail, <i>Athearnia
anthonyi</i>, using allozyme electrophoresis. The Nautilus 110: 97 - 101. [<a href="https://www.fwgna.org/dillonr/dillon&ahlstedt.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> Dillon, R.T., and C. Lydeard (1998) Divergence among
Mobile Basin populations of the pleurocerid snail genus, Leptoxis, estimated by
allozyme electrophoresis. Malacologia.
39: 111-119. [<a href="https://www.fwgna.org/dillonr/dillon&lydeard98.pdf" target="_blank">pdf</a>] For more, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Mobile Basin II: Leptoxis lessons [<a href="https://fwgna.blogspot.com/2009/09/mobile-basin-ii-leptoxis-lessons.html" target="_blank">15Sept09</a>]</li><li>Intrapopulation gene flow, the Leptoxis of the Cahaba, and
the striking of matches [<a href="https://fwgna.blogspot.com/2021/11/intrapopulation-gene-flow-leptoxis-of.html" target="_blank">2Nov21</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[20]</span></b> Morrison, J. (1971) <i>Athearnia</i> a new name for a genus of
pleurocerid snails. The Nautilus 84:110
– 111.</p><p class="MsoNormal"><b><span style="color: #783f04;">[21]</span></b> U.S. Fish and Wildlife Service (1994) Endangered and
threatened wildlife and Plants; Determination of endangered status for the
Royal Snail and Anthony’s Riversnail.
Federal Register 59: 17994 – 17998. [<a href="https://www.govinfo.gov/content/pkg/FR-1994-04-15/pdf/FR-1994-04-15.pdf#page=88" target="_blank">FR-1994-04-15</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[22]</span></b> This sort of thing pisses me off royally. Science and public policy are not
compatible. And anybody who thinks
otherwise is sharpening a knife to kill the former.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-29150319365579693312023-03-07T11:14:00.009-05:002023-11-28T09:54:48.434-05:00Malacological Mysteries: What was Planorbis glabratus?<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023c) Malacological Mysteries: What Was Planorbis glabratus? Pp 319 – 333 <b>in</b> The Freshwater Gastropods of North America Volume 7, <i>Collected in Turn One, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>In Volume 1 of the Journal of the Academy of Natural Sciences
of Philadelphia, Part 2 (June 1818) The Father of American Malacology, Thomas
Say, described a new freshwater gastropod as follows <b><span style="color: #783f04;">[1]</span></b>:</p><p></p><blockquote><p><span style="font-size: x-small;"><i>Planorbis glabratus</i>.—Shell sinistral; whorls about five,
glabrous or obsoletely rugose, polished, destitute of any appearance of carina;
spire perfectly regular, a little concave ; umbilicus large, regularly and
deeply concave, exhibiting all the volutions to the summit; aperture declining,
remarkably oblique with respect to the transverse diameter.</span></p><p><span style="font-size: x-small;">Breadth nearly nine-tenths of an inch. Inhabits South
Carolina. Cabinet of the Academy.</span></p><p><span style="font-size: x-small;">Presented to the Academy by Mr. L'Hermenier of Charleston,
an intelligent and zealous naturalist; he assured me that this species inhabits
near Charleston. It somewhat resembles large specimens of the P. trivolvis of
the American edition of Nicholson's Encyc., but differs in the total absence of
carina, and in having a more smooth and polished surface, as well as a
declining and more oblique aperture, and a more profound and much more regularly
concave umbilicus.</span></p></blockquote><p></p><p>Alas, Thomas Say did not offer us a figure of his new
planorbid species, and alack, all of Say’s type material has been lost. The 139 words I have quoted above are the sum
total of everything we know for a fact about <i>Planorbis glabratus</i>.</p><p>But to be fair, as strings of 139 words go, Say’s 139 are pretty darn vivid. The adjectives
“glabrous” and “polished” effectively distinguish the shell of Say’s new
planorbid from his (1817) <i>P. trivolvis</i> <b><span style="color: #783f04;">[2]</span></b>, widely distributed across North
America. “Nine tenths of an inch” is
unusually large for a planorbid, and “whorls about five” suggests an
exceptionally tight coil.</p><p class="MsoNormal"><o:p></o:p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1rAlw4jCflk0WFNHaGBHXQrAuu-3Yj5vffm1djSCj8Dnk1Wlo4oT-wMkW_W-jCVuLint6XJXSrXsZPaqbcNSrAM2cTOyu1lNDSF3DJchCsmQowf9VcQA6d1wWZGBI1hH-nhuLh9BnD65xUp3C9ge5EJAiNUiU0oln2ziXgxgzEv4_AW8mXCOEGY1yNA/s575/P-glabratus-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="412" data-original-width="575" height="229" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1rAlw4jCflk0WFNHaGBHXQrAuu-3Yj5vffm1djSCj8Dnk1Wlo4oT-wMkW_W-jCVuLint6XJXSrXsZPaqbcNSrAM2cTOyu1lNDSF3DJchCsmQowf9VcQA6d1wWZGBI1hH-nhuLh9BnD65xUp3C9ge5EJAiNUiU0oln2ziXgxgzEv4_AW8mXCOEGY1yNA/s320/P-glabratus-montage.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Planorbis glabratus</i> from Haldeman <b><span style="color: #783f04;">[3]</span></b> and Binney <b><span style="color: #783f04;">[4]</span></b></span></td></tr></tbody></table><p class="MsoNormal">In any case. Two
monographers of the nineteenth century, Haldeman in 1844 <b><span style="color: #783f04;">[3]</span></b> and Binney in 1865
<b><span style="color: #783f04;">[4]</span></b>, took shots at publishing figures of <i>Planorbis glabratus</i>, the former at
left above, the latter at right. Neither
author offered a scale bar or a measurement, implying a 1:1 reproduction. Both of those figures appear to depict shells
with zillions of fine ridges, which make them look suspiciously like dirt
common <i><a href="https://www.fwgna.org/species/planorbidae/h_trivolvis.html" target="_blank">Helisoma trivolvis</a></i> <b><span style="color: #783f04;">[5]</span></b>.</p>
<p class="MsoNormal">Henry Pilsbry wasn’t buying it.<span style="mso-spacerun: yes;"> </span>We have already reviewed at great length, in
three posts to date and counting, The Elderly Emperor’s landmark paper of 1934
<b><span style="color: #783f04;">[6]</span></b> describing <i>Seminolina</i> as a new Floridian subgenus of <i>Helisoma</i> and assigning
to it four species, including <i>scalare</i> (Jay 1839) and <i>duryi</i> (Wetherby 1879).<span style="mso-spacerun: yes;"> </span>Pilsbry recognized three subspecies of <i>duryi</i>
previously described and added three fresh ones, including a new scalariform
(“flat topped”) subspecies <i>seminole</i>, about which we obsessed last month.<span style="mso-spacerun: yes;"> </span>And he also described a new subspecies at the
other end of the spectrum, <i>Helisoma duryi eudiscus</i>, bearing a broad,
compressed, tightly coiled shell, shown in the figure below.<span style="mso-spacerun: yes;"> </span>And he observed:</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">“This form [<i>eudiscus</i>] is what Bryant Walker <b><span style="color: #783f04;">[7]</span></b> and the
writer [Pilsbry] called <i>Planorbis glabratus</i> Say. None of the specimens seen approach the
dimensions given by Say, and the locality given by him is over 200 miles
northward. I have elsewhere discussed
the identification of his [Say’s] species.”<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgfNb9oPA1_kcJbLAXVdx4au5CMznbnDdlfoRukDnliJHVDwSmJk2iJ4se5qx1yWSQhxsWkc3TfLoJkE7XwQibnAFepzKE6isUXGk_oGkr39IY536iRDiOlglPSmpwNpPYlgy9lo4EHxjxO6zdPlvuMy-xjIF11QyuwBJsoxmPTr_GEVKG_y4td0zvnQ/s612/H-duryi-eudiscus-Pilsbry-fix.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="612" data-original-width="274" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgfNb9oPA1_kcJbLAXVdx4au5CMznbnDdlfoRukDnliJHVDwSmJk2iJ4se5qx1yWSQhxsWkc3TfLoJkE7XwQibnAFepzKE6isUXGk_oGkr39IY536iRDiOlglPSmpwNpPYlgy9lo4EHxjxO6zdPlvuMy-xjIF11QyuwBJsoxmPTr_GEVKG_y4td0zvnQ/w142-h320/H-duryi-eudiscus-Pilsbry-fix.jpg" width="142" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>H. duryi eudiscus</i> <span style="color: #783f04;"><b>[6]</b></span></span></td></tr></tbody></table><br /></span></blockquote><p></p><p class="MsoNormal">That “elsewhere” turned out to be “immediately
following.” Because the next section of
his 1934 paper was headed, “Species Recorded from Florida in Error.” Here Pilsbry elaborated the opinion (first
expressed by Wetherby) that neither the shell figured by Haldeman, nor the
shell figured by Binney, matched Thomas Say’s original description. And he agreed with Wetherby that South
Florida is indeed inhabited by populations of large, flat, shiny, tightly
coiled <i>Helisoma</i> that do match Say’s description, which (he had just suggested)
might be identified as <i>Helisoma duryi eudiscus</i>.
But…</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">“A difficulty with this identification [of <i>eudiscus</i> as <i>glabrata</i>] is that no such shell has been found in Georgia or in
South Carolina (Say’s locality); and there is little probability that a shell
from the lower and middle parts of peninsular Florida would have been collected
prior to 1818.”</span></blockquote><p></p><p class="MsoNormal">Let me repeat that.
That is important. <b> Pilsbry
himself, and Bryant Walker, and Albert Wetherby, all thought that the shells
borne by planorbid populations Pilsbry was describing as <i>Helisoma duryi
eudiscus</i> matched Say’s description of <i>Planorbis glabratus</i>.</b> But Pilsbry did not think that <i>Helisoma duryi</i>
ranged as far north as Charleston. And
he didn’t know of any <i>eudiscus</i> anywhere reaching a diameter approaching
“nine-tenths of an inch” in any case.
Remember all that. You’re going
to need it after the intermission.</p><p class="MsoNormal">Pilsbry then went on to propose a rather elaborate
hypothesis, as follows:</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">“Say received the type specimen of <i>P. glabratus</i> from Mr.
L'Herminier of Charleston, S. C. His description applies well to the Antillean
<i>Planorbis guadaloupensis</i> Sowb. I was thus led to inquire into the travels of
L'Herminier. I applied to Mr. E. B. Chamberlain, Director of the Charleston
Museum, who [confirmed that L’Herminier] came to Charleston about 1814 from
Guadeloupe bringing 'an extensive collection of specimens, the fruit of twenty
years application, expense and industry, which he offered to the Society [The
Literary and Philosophical Society of South Carolina]. Dr. L'Herminier was
appointed superintendent or curator of the Society's museum, and served until
1819, at which time he returned to Guadeloupe. […] It seems quite likely
therefore that the type of <i>Planorbis glabratus</i> was one of the specimens
L'Herminier brought from Guadeloupe, and which he subsequently thought (or Say
inferred) that he had picked up around Charleston.”</span></blockquote><p></p><p class="MsoNormal">I know it must seem to you, my loyal and longsuffering
readership, that your eccentric guide to malacological triviality most arcane
has developed an obsession most inexplicable with an obscure 1934 paper
published in the Proceedings of the Academy of Natural Sciences of
Philadelphia, having posted three essays dwelling on the work thus far, plus a
large fraction of a fourth essay presently unfolding. Why, you must be wondering, can’t you let
those 44 pages of densely-packed esoterica go, Dillon, for God sake? Well, I regret to inform my readership, we
haven’t even touched the more important half of Pilsbry’s 1934 paper yet.</p><p class="MsoNormal">Pilsbry’s full title was, “Review of the Planorbidae of
Florida, with Notes on Other Members of the Family.” And by “notes,” Pilsbry meant to propose a
taxonomic revision of the entire planorbid fauna of the New World.</p><p class="MsoNormal"></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvtoYLIX6r09dMIZaoso_MZT5zGLEmHr6WyUA6DdVdfelfrHifb7Uod3YvmvJ2_4pjo6RS8zJKwvlYAnXtjAXrGsPzvL4dLcc8VV1WYq4iPXdjfeupJetKl9k-sX8gLzRaud1a4aZ93NHlIYoTm2OmJ5nKuIb1HQuqNb3o-lYWvCfgtGpAf4VjsT50fw/s629/A-glabratus-Pilsbry-montage.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="629" data-original-width="300" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvtoYLIX6r09dMIZaoso_MZT5zGLEmHr6WyUA6DdVdfelfrHifb7Uod3YvmvJ2_4pjo6RS8zJKwvlYAnXtjAXrGsPzvL4dLcc8VV1WYq4iPXdjfeupJetKl9k-sX8gLzRaud1a4aZ93NHlIYoTm2OmJ5nKuIb1HQuqNb3o-lYWvCfgtGpAf4VjsT50fw/s320/A-glabratus-Pilsbry-montage.jpg" width="153" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Australorbis glabratus</i> <b><span style="color: #783f04;">[6]</span></b></span></td></tr></tbody></table>So, in the second half of his paper, Pilsbry recognized
eight previously described genera in The Americas: <i>Tropicorbis</i> and <i>Drepanotrema</i>
from Way Down South, <i>Carinifex</i> and <i>Parapholyx</i> from Way Out West, and our old
friends from right here at home: <i>Helisoma</i>, <i>Planorbula</i>, <i>Menetus</i> and
<i>Gyraulus</i>. To these he added a ninth
genus, a newly described <i>Australorbis</i>.
And as the type of his new genus, he selected “<i>P. guadaloupensis</i> Sowb. =
<i>A. glabratus</i> (Say).”<p></p><p class="MsoNormal">The population of “<i>P. guadeloupensis</i> = <i>A. glabratus</i>” that
Pilsbry examined was collected from Puerto Rico. They bore large, flat, shiny, tightly coiled
planispiral shells not much different from the Florida populations that he and
Wetherby and everybody else had been identifying as <i>Helisoma duryi</i>, especially
the subspecies “<i>eudiscus</i>.” But
anatomically the Puerto Rico population was quite distinct from <i>Helisoma</i>,
missing a penial gland entirely <b><span style="color: #783f04;">[8]</span></b>.</p><p class="MsoNormal">Both Baker in 1945 <b><span style="color: #783f04;">[9]</span></b> and Hubendick in 1955 <b><span style="color: #783f04;">[10] </span></b>accepted
Pilsbry’s Guadeloupe hypothesis for the origin of Thomas Say’s <i>Planorbis
glabratus</i> uncritically, which pretty much set it in concrete, and both accepted
<i>Australorbis</i> as a natural genus in which to place it. Baker dissected and figured his sample from
Puerto Rico; Hubendick’s came from Venezuela.
Baker also gathered a fairly large list of synonyms under <i>glabratus</i>,
beyond the <i>guadeloupensis</i> suggested by Pilsbry, including <i>olivaceus</i> (Spix) from
Brazil, <i>refulgens</i> (Dunker) from Santo Domingo, <i>lugubris</i> (Wagner) from Surinam,
and <i>blauneri</i> (Germain) from Venezuela.
So, by 1955, the range of <i>Australorbis glabratus</i> was given as Venezuela
to Argentina and throughout the Caribbean.</p><p class="MsoNormal">Yet another taxonomic change was looming, however, even as
Hubendick labored over his 1955 monograph.
In 1910, the Englishman H.B. Preston had proposed the genus <i>Biomphalaria</i>
to hold his new <i>Biomphalaria smithi</i> from the Congo/Uganda border <b><span style="color: #783f04;">[11]</span></b>, and
during the 40 years that followed, momentum built to allocate an increasing
number of African species to Preston’s genus.
And indeed, species from the New World as well. Hubendick wrote:</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">"The <i>Biomphalaria</i> tribe includes the following genera:
<i>Biomphalaria, Afroplanorbis, Australorbis, Tropicorbis, Taphius</i>, and
<i>Platytaphias</i> and probably <i>Syrioplanorbis</i>…The whole tribe is anatomically so
homogeneous that it is doubtful if the present separation into genera can be
maintained.”</span></blockquote><p></p><p class="MsoNormal">Doubtful, indeed.
Begging your indulgence, please allow me to back up and get a fresh
start on this entire story, from an entirely fresh perspective<b><span style="color: #783f04;"> [12]</span></b>. In 1851 the German physician Theodor Bilharz
discovered that a widespread and debilitating disease affecting a large fraction
of the population of Egypt was caused by a parasitic worm. And in 1915 the Scottish physician Robert
Thomson Leiper identified two species of the digenetic trematode genus
<i>Schistosoma</i> as the helminthological culprits for two different forms of this same
disease and simultaneously worked out the intermediate hosts for both:
“<i>Planorbis boissyi</i>” for <i>Schistosoma mansoni</i> and “<i>Bulinus spp</i>” for <i>Schistosoma
haematobium</i>.</p><p class="MsoNormal">The form of the disease caused by <i>Schistosoma mansoni</i> had
also been a problem for many years in the New World tropics, as well as in the
Old. And in 1916, almost immediately
after Lieper published his results on <i>Schistosoma mansoni</i> in Egypt, the
Brazilian Adolpho Lutz reported the successful development of <i>S. mansoni
</i>miricidia in a snail he identified as “<i>Planorbis olivaceus = P. bahiensis</i>.” Then in 1917, the Venezuelan Juan Iturbe
obtained similar results with a planorbid population he identified as
“<i>Planorbis guadelupensis</i>.”</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFGw0Tc0VVvIhKuVqG3MrlmZxcLoyd5qO0ZBUcPM6p8wzUf-2FJuy_sy2C4cj6JZptiVQ4SJhawdmSHTEXkODmLjJaisAj3CdO9tqCksj431Wq5v-mv3H4MxXoIuo3OXl_HOS1jN-HUBZrJ_oF9lH_HdzHjPKr7CPwH5XYeaRQPUKKTozRe3zry5amBw/s2741/Castillo-Schistosome-figure.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2360" data-original-width="2741" height="277" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFGw0Tc0VVvIhKuVqG3MrlmZxcLoyd5qO0ZBUcPM6p8wzUf-2FJuy_sy2C4cj6JZptiVQ4SJhawdmSHTEXkODmLjJaisAj3CdO9tqCksj431Wq5v-mv3H4MxXoIuo3OXl_HOS1jN-HUBZrJ_oF9lH_HdzHjPKr7CPwH5XYeaRQPUKKTozRe3zry5amBw/w320-h277/Castillo-Schistosome-figure.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Castillo et al. <b><span style="color: #783f04;">[13]</span></b></span></td></tr></tbody></table><p class="MsoNormal">Was Pilsbry unaware of Iturbe’s research when he synonymized
<i>Planorbis guadelupenis</i> under <i>Australorbis glabratus</i>? Was Baker unaware of Lutz’s work when he did
the same thing to <i>Planorbis olivaceus</i>?
Neither Pilsbry nor Baker mentioned anything about the parasitological
importance of the taxonomic judgements they were making. But together, they made <i>Australorbis
glabratus</i> into a Latin binomen that appeared in the abstracts of scores of papers directly bearing on issues of human health through the 1940s into the early 50s.</p><p class="MsoNormal">By 1955, Hubendick did think it worth mention that “several
planorbids act as intermediate hosts for many trematodes, including
schistosomes” in his introduction,
although he did not hear the call to develop that theme until the 84th page of his 90 page
work. There he reiterated his opinion
that <i>Australorbis</i> (and <i>Tropicorbis</i>) did not differ “in any essential way” from
<i>Biomphalaria</i> (or <i>Afroplanorbis</i>). But he
continued, “although the most natural course would be to unite all the genera
into one genus,” to do so “would certainly cause much confusion and trouble to
works in medical parasitology who are now familiar with names which are in
current use.” Thus, Hubendick advocated
retaining <i>glabrata</i> (Say 1818) in <i>Australorbis</i>.</p><p class="MsoNormal">All I can figure is that by the time he wrote those words,
Hubendick had already been out-voted.
Because in 1954 the World Health Organization had convened an
international “Study-Group” consisting of Alves, Berry, Hubendick, LeRoux,
Mandahl-Barth and Ranson. And by 1955,
the joint opinion of the group had been published <b><span style="color: #783f04;">[14]</span></b>:</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">“It has long been recognized that the known species which
serve as the intermediate hosts for <i>S. mansoni</i> are genetically the same and
that all have probably been derived from common stock. It was therefore agreed that these and their
related species should be united into a single genus <i>Biomphalaria</i>, and that the
genera <i>Australorbis, Afroplanorbis</i>, and <i>Tropicorbis</i> should be considered
synonyms.”</span></blockquote><p></p><p class="MsoNormal">And all other researchers worldwide fell in line. So today, a quick reference to the NCBI PubMed
database returns 3,438 hits to the search term “<i>Biomphalaria glabrata</i>,” the
intermediate host of schistosomiasis in the New World, 1947 to present.</p><p class="MsoNormal">OK, I’m going to take a 20-minute break for some fresh
air. While I’m gone, here’s a question
for your consideration. What would
happen if Thomas Say’s sample of <i>Planorbis glabrata</i> really was collected from
Charleston, as he was assured by that “intelligent and zealous naturalist,”
Felix L'Hermenier? Discuss amongst
yourselves …</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhksgXgXOSynABKiWmiUOKiSQGvI4n_oMm_3rdYEL424pF0FTF_tD3BCF9s0n4xZikGpGDJdIbC0hsD7Csi_QBr6s3ej8c8A3zauBKOQUNv9-og7poflE1D21sZLIOCh-5X4pVN_qENmatY4AUU1VVbMv__OUZs2qUwO8NdEp0CYiRfOfydWNgoQehNrA/s1485/Intermission-GWTW.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1080" data-original-width="1485" height="233" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhksgXgXOSynABKiWmiUOKiSQGvI4n_oMm_3rdYEL424pF0FTF_tD3BCF9s0n4xZikGpGDJdIbC0hsD7Csi_QBr6s3ej8c8A3zauBKOQUNv9-og7poflE1D21sZLIOCh-5X4pVN_qENmatY4AUU1VVbMv__OUZs2qUwO8NdEp0CYiRfOfydWNgoQehNrA/s320/Intermission-GWTW.jpg" width="320" /></a></div><p class="MsoNormal">… and I’m back. I
just drove over to Charles Towne Landing State Park, about a mile from my house
here in the West Ashley neighborhood of Charleston. They have a couple pretty little spring-fed
lakes over there. And the figure below
shows what I found.</p><p class="MsoNormal">These shells are a near-perfect match to every word in
Thomas Say’s 1818 description of <i>Planorbis glabratus</i>, and don’t tell me that
they aren’t. They are “destitute of any
appearance of carina,” “polished” to the point of “glabrous.” Their spires are (indeed) “a little concave,
umbilicus large,” and apertures (indeed) “remarkably oblique.” The diameter of the middle specimen, viewed
edge-on, is 22.6 mm = 0.89 inch.</p><p class="MsoNormal">This is the "Population C" I sampled for our colleague Cindy Norton back in 2018. My readership will remember that Cindy's breeding experiments returned no evidence of
reproductive isolation between population C and a sample of <i><a href="https://www.fwgna.org/species/planorbidae/h_scalaris_scalaris.html" target="_blank">Helisoma scalare scalare</a></i> (“F”) I collected for her from way down in the Florida Everglades <b><span style="color: #783f04;">[15]</span></b>. So, since the shells borne by Population C are
planispiral, the most modern, least-controversial identification for the Charles Towne Landing
population is currently <i><a href="https://www.fwgna.org/species/planorbidae/h_scalaris_duryi.html" target="_blank">Helisoma scalare duryi</a></i> <b><span style="color: #783f04;">[16]</span></b>.</p><p class="MsoNormal"></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-OyyB0BaT80TSM532jF3brEdefpOVpyACd8Ka7XdBEWQ875bRdQ3xGyewWZTa-uF7GPdAObCLfPkJppFI2r7ZsnvhpzpcfaoCfvKOvEr9mCn6B-oktO_8hhJhKKPREHLkpaPyFQcps8Lhp5T4VCzFmSJCRvLzgv4OypmlO6ZwCF4ynPr5vLw_SwJiAw/s1590/H_duryi-Chas.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1590" data-original-width="925" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj-OyyB0BaT80TSM532jF3brEdefpOVpyACd8Ka7XdBEWQ875bRdQ3xGyewWZTa-uF7GPdAObCLfPkJppFI2r7ZsnvhpzpcfaoCfvKOvEr9mCn6B-oktO_8hhJhKKPREHLkpaPyFQcps8Lhp5T4VCzFmSJCRvLzgv4OypmlO6ZwCF4ynPr5vLw_SwJiAw/s320/H_duryi-Chas.jpg" width="186" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Charles Towne Landing SP</span></td></tr></tbody></table>But might they be <i>Planorbis glabratus</i>? The only quibble one might offer to the identification of
Population C as <i>P. glabratus</i> could be the whorl count, which Say
described as “about five.” I really
can’t count more than four whorls in the shells figured at left. But it turns out that other populations here
in the Charleston area do sometimes bear much narrower, more tightly coiled
shells demonstrating five whorls and more. <p></p><p class="MsoNormal">The figure at the top of the montage down below was borrowed from
a [<a href="https://fwgna.blogspot.com/2004/11/gigantic-pulmonates.html" target="_blank">29Nov04</a>] essay I wrote about a gigantic <i>Helisoma</i> population inhabiting an
ornamental pond outside a commercial office park here West of the Ashley, about
a mile from Charles Towne Landing. And
the two figures beneath it were borrowed from a [<a href="https://fwgna.blogspot.com/2005/02/shell-morphology-current-and-substrate.html" target="_blank">18Feb05</a>] essay I wrote about a
dimorphic <i>Helisoma</i> population in a subdivision called “Wakendaw Lakes” in Mt
Pleasant, a Charleston suburb east of the Cooper River. I initially identified both of those
populations as “<i>Helisoma trivolvis</i>,” back before the scales fell from my eyes
in 2021 <b><span style="color: #783f04;">[17]</span></b>, but their best modern identification would again be <i>Helisoma
scalare duryi</i>, same as the Charles Towne Landing population.</p><p class="MsoNormal">Pilsbry and Baker would almost certainly have identified the
shells from Charles Towne Landing State Park above as <i>Helisoma duryi normale</i>
<b><span style="color: #783f04;">[16]</span></b>. Those from the office park and the
Wakendaw Lakes subdivision below I feel fairly certain would have been <i>Helisoma duryi eudiscus</i>. And both
Pilsbry and Baker would have been shocked to learn that any planorbid populations
bearing shells of such flamboyantly <i>duryi</i> morphology might inhabit waters anywhere north
of Florida <b><span style="color: #783f04;">[18]</span></b>.</p><p class="MsoNormal">But in fact, I am now aware of six populations of <i>H. scalare
duryi</i> in Charleston County alone, and many others scattered elsewhere around
coastal South Carolina as far north as the vicinity of Myrtle Beach, and three
in coastal Georgia as well <b><span style="color: #783f04;">[19]</span></b>. Plus,
Binney’s historic record from St. Simon’s Island, GA, brings the Georgia
populations up to four <b><span style="color: #783f04;">[5]</span></b>.</p><p class="MsoNormal">Although most of the Carolina and Georgia populations of <i>H.
scalare duryi</i> of which I am aware inhabit disturbed environments today, my
biological intuition suggests to me that this northern end of their range is as natural as their southern one. Binney’s collection dates prior to 1865. But even if the occurrence of <i>Helisoma
scalare duryi</i> here in the Charleston area is artificial, if the introduction
occurred prior to 1818, the point I am trying to argue will not be affected.</p><p class="MsoNormal"></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi40FsYppn7Jam3fa4OgBfsy2FEInBc4aemEM6MPLRyxTmD7qbThAUR_tAZsDxFKYuaG8TqfP3P3i36zVIOdsof93Im93yOvvR2dll3myr44hc4vUD07wvQUofkGnZq3sgoTMVs2G5u7t1c4wZwBJjEMTCciqeFVgXbr21wHlcSSDKsoqtvNBa9iZrl7w/s1820/Charleston-eudiscus-montage.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1820" data-original-width="780" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi40FsYppn7Jam3fa4OgBfsy2FEInBc4aemEM6MPLRyxTmD7qbThAUR_tAZsDxFKYuaG8TqfP3P3i36zVIOdsof93Im93yOvvR2dll3myr44hc4vUD07wvQUofkGnZq3sgoTMVs2G5u7t1c4wZwBJjEMTCciqeFVgXbr21wHlcSSDKsoqtvNBa9iZrl7w/s320/Charleston-eudiscus-montage.jpg" width="137" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Office Park & Wakendaw</span></td></tr></tbody></table>Here in 2023 there is no reason to doubt that the shells in
Thomas Say’s hand when he described <i>Planorbis glabratus</i> in 1818 were, indeed,
collected in Charleston, South Carolina, as the “intelligent and zealous
naturalist” Felix L'Hermenier assured him.
Pilsbry’s (1934) hypothesis that L’Hermenier’s shells came from
Guadeloupe was predicated on Pilsbry’s erroneous belief that <i>Helisoma duryi</i>,
specifically the tightly compressed subspecies he described as <i>H. duryi
eudiscus</i>, did not range north of Florida.
Now that we know that such populations do, in fact, inhabit many ponds
in the Charleston area, identified as <i>Helisoma scalare duryi</i> today, Pilsbry’s Guadeloupe hypothesis has become entirely unnecessary.<p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">So by the letter of the International Code of Zoological
Nomenclature, all those Floridian nomina of planorbids: <i>scalare</i> (Jay 1839),
<i>duryi</i> (Wetherby 1879), and all the subspecies proposed by Pilsbry and others,
like <i>eudiscus</i> and <i>seminole</i>, are junior synonyms of <i>glabrata </i>(Say 1818). Which means that by the letter of the Code of
Zoological Nomenclature, all those tropical planorbid populations that host
<i>Schistosoma mansoni</i> in the New World, originally identified as <i>guadeloupensis</i>
(Sowerby), <i>olivacea</i> (Spix) and many other names <b><span style="color: #783f04;">[20]</span></b>, are not correctly
identified as <i>Biomphalaria glabrata</i>.
They must be called something else.
I don’t know what. I don’t want
to know.</p><p class="MsoNormal">Because what I have uncovered here is a bomb. Actually, it’s more like one of those rusty
old artillery rounds that utility crews still occasionally dig up under the
streets of Charleston, fired by Union cannon during the bombardment of
1863-65. It’s a dud. That old thing can’t possibly be dangerous,
can it?</p><p class="MsoNormal">Well, yes, it can. I
myself was caught in the shrapnel when Jack Burch unearthed just such a dud in
the early 1980s <b><span style="color: #783f04;">[22]</span></b>. The genus <i>Elimia
</i>was shot into the air by H & A Adams in 1854 to contain an odd-lot
assortment of pleurocerid nomina, hit the ground with a thud, and was buried
and forgotten for 120 years, explicitly rejected by Tryon, Walker, Goodrich, and
all other authorities of the day in favor of Isaac Lea’s <i>Goniobasis</i>. But even as I was defending my dissertation
on <i>Goniobasis</i> in Philadelphia, Jack Burch was exhuming <i>Elimia</i> in Ann Arbor and
synonymizing <i>Goniobasis</i> underneath it.
This he did for no scientific reason whatsoever, motivated entirely by a
sense of romantic duty to the Code of Zoological Nomenclature. The confusion and misunderstanding persist to
the day <b><span style="color: #783f04;">[23]</span></b>.</p><p class="MsoNormal">So, it turns out that when Charleston utility crews unearth
unexploded Yankee ordinance, no matter how old and decrepit the round might be,
they don’t rebury it. They call the bomb
squad. And the bomb squad doesn’t try to
“defuse” that rusty old thing in some fine and sophisticated manner. They just blow it up.</p><p class="MsoNormal">So, this month I have spent 3,028 words digging up a rusty
old bomb called “<i>Planorbis glabratus</i>.” I
now mean to blow it up. <b><i>Planorbis
glabratus</i> Say 1818 must remain a senior synonym of <i>Planorbis guadeloupensis
</i>Sowerby, 1822</b>, as proposed by Pilsbry in 1934, and senior as well over all
tropical and Caribbean planorbid taxa more recently described and subsequently
placed underneath it <b><span style="color: #783f04;">[20]</span></b>. To redefine
Say’s 1818 taxon as a senior synonym of John Clarkson Jay’s 1839 <i>Paludina
scalaris</i> or Wetherby’s 1879 <i>Helisoma duryi</i> would be a terrible disservice to
the cause of science. I won’t do it, and
don’t any of the rest of you try.</p><p class="MsoNormal">Because here’s the important thing. And I am dead serious about this, so listen
up. <b>Biological nomenclature must serve
science. </b> To change the specific name by
which we have referred to the intermediate host of schistosomiasis in the New
World would create epic levels of confusion, mischief, and mayhem for
absolutely, utterly no reason other than an obscure point of law. <i>Biomphalaria glabrata</i> must remain
<i>Biomphalaria glabrata</i>, as that taxon is currently understood by the scientific community, for
the sake of science, now and forever, amen.</p><p class="MsoNormal"><br /></p><p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Say, T. (1818) Account of two new genera, and several
new species, of fresh water and land shells.
Journal of the Academy of Natural Sciences of Philadelphia 1(2): 276 –
284.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> The shell of Helisoma trivolvis is “thread striate,”
noticeable especially in juveniles, which tends yield a duller luster. See:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Collected in Turn One [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Haldeman, S.S. (1844) [not “1841”] A monograph of the
freshwater univalve Mollusca of the United States, Number 7 Philadelphia: Cary & Hart, Dobson, and
Pennington. 32 pp, 4 plates.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Binney, W.G. (1865) Land and fresh water shells of North
America Part II, Pulmonata Limnophila and Thalassophila. Smithsonian
Miscellaneous Collections 143: 1 – 161.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Haldeman’s specimen came from “Mexico (?)” and Binney’s
specimen came from St. Simon’s Island, GA, which means, ironically, that
Binney’s (at least) was almost certainly correctly identified as <i>Planorbis
glabratus,</i> in the contemporary meaning of that name. Read on and see footnote
<b><span style="color: #783f04;">[17]</span></b>.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Pilsbry, H. A. (1934) Review of the Planorbidae of
Florida, with notes on other members of the family. Proceedings of the Academy of Natural
Sciences of Philadelphia 86: 29 – 66.
For a review, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The Emperor Speaks [<a href="https://fwgna.blogspot.com/2020/12/the-emperor-speaks.html" target="_blank">3Dec20</a>]</li><li>The Emperor, the Non-child, and the Not-short Duct [<a href="https://fwgna.blogspot.com/2021/02/the-emperor-non-child-and-not-short-duct.html" target="_blank">9Feb21</a>]</li><li>New Clothes for The Emperor [<a href="https://fwgna.blogspot.com/2023/02/new-clothes-for-emperor.html" target="_blank">7Feb23</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Walker, B. (1918) A synopsis of the classification of
the freshwater Mollusca of North America, North of Mexico, and a catalogue of
the more recently described species, with notes. Univ. Mich. Mus. Zool. Misc. Publ. 6: 1 -
213.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> The distinction between Pilsbry’s new genus <i>Australorbis</i>
and his previously described <i>Tropicorbis</i> was negligible, however. And I quote: “<i>P. guadaloupensis</i> differs from
<i>Tropicorbis</i> by its extremely short almost sessile spermatheca, the relatively
shorter upper sac of the penis, and by the denticulation of the marginal teeth,
in which the denticles remain widely separated in an inner and an outer
series.” Good grief.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> Baker, F.C. (1945) The Molluscan Family Planorbidae.
Urbana: University of Illinois Press.
530 pp.</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Hubendick, B. (1955) Phylogeny in the Planorbidae.
Trans. Zool. Soc. London 28: 453-542.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Preston, H. B. (1910). Additions to the non-marine
molluscan fauna of British and German East Africa and Lake Albert Edward. The
Annals and Magazine of Natural History. (8) 6 (35): 526-536, pl. 7-9.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> I thank Sam Loker for pointing me to an excellent
reference on the history of schistosomiasis research, upon which I have based
the brief review above:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Grove, David I. (1990) A History of Human Helminthology. C.A.B.International,
Wallingford.</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> Castillo, M.G., J.E. Humphries, M.M. Mourao, J.
Marquez, A. Gonzalez, C.E. Montelongo (2020) <i>Biomphalaria glabrata</i> immunity:
Post-genome advances. Developmental
& Comparative Immunology 104: 103557.</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Alves, W., E.G. Berry, B. Hubendick, P.L. LeRoux, G.
Mandahl-Barth, and G. Ranson (1954). Bilharzia snail vector identification and
classification (Equatorial and South Africa).
Report of a Study-Group. World
Health Organization Technical Report Series 90: 1 – 24.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15] </span></b>For the complete story of Cindy Norton’s breeding
experiments, read this series of essays:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Flat-topped Helisoma of The Everglades [<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>]</li><li>Foolish Things with Helisoma duryi [<a href="https://fwgna.blogspot.com/2020/11/foolish-things-with-helisoma-duryi.html" target="_blank">9Nov20</a>]</li><li>Collected in Turn One [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> I just proposed lowering Wetherby’s (1879) <i>duryi</i> to
subspecific status under Jay’s (1839) <i>scalaris</i> last month. But the build-up was a lengthy one, extending
back to early 2021. Work backwards from
this essay if you want the complete</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>New Clothes for the Emperor [<a href="https://fwgna.blogspot.com/2023/02/new-clothes-for-emperor.html" target="_blank">7Feb23</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> Although I reported the “scales falling from my eyes”
regarding the Charleston area <i>Helisoma</i> populations in January of 2021, the
build-up was a lengthy one, extending back to 2018. Work backwards from this essay if you want
the complete story:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Collected in Turn One [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[18] </span></b>In my dreams, I march right up to Philadelphia with a
Charleston sample of<i> Helisoma scalare duryi</i> under my arm and present it to
Henry Pilsbry. He accepts it, thanks me,
and writes, “another notorious liar” on the back of the label.</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Dr. Henry A. Pilsbry was a Jackass [<a href="https://fwgna.blogspot.com/2021/01/dr-henry-pilsbry-was-jackass.html" target="_blank">26Jan21</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> Toward the bottom of my 5Jan21 essay, I mentioned “one
population of <i>H. duryi</i> in coastal Georgia" as well as “15 populations in coastal
South Carolina.” More recently I have
discovered two additional populations of <i>H. scalare duryi</i> in Savannah, bringing the coastal
Georgia count up to three.</p><p class="MsoNormal"><b><span style="color: #783f04;">[20]</span></b> Here’s a list of junior synonyms that have been placed
under <i>glabrata</i> (Say 1818), collected both from Baker <b><span style="color: #783f04;">[9]</span></b> and from Malek
<b><span style="color: #783f04;">[21]</span></b>: <i>guadeloupensis</i> (Sowerby),
<i>christopherensis</i> (Pils), <i>olivaceus</i> (Spix), <i>refulgens</i> (Dunker), <i>lugubris</i>
(Wagner), <i>blauneri</i> (Germain), <i>ferrugineus</i> (Spix), <i>nigricans</i> (Spix), <i>albescens</i>
(Spix), <i>viridis</i> (Spix), <i>lundii</i> (Beck), <i>cumingianus</i> Dunker, <i>becki</i> Dunker,
<i>bahiensis</i> Dunker, and <i>xerampelinus</i> Drouet.</p><p class="MsoNormal"><b><span style="color: #783f04;">[21]</span></b> Malek, E. (1985)
Snail hosts of schistosomiasis and other snail-transmitted diseases in
tropical America: A manual. Washington, D.C., Pan American Health
Organization. 325 pp.</p><p class="MsoNormal"><b><span style="color: #783f04;">[22]</span></b> For a complete review of the controversy, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Goniobasis and Elimia [<a href="https://fwgna.blogspot.com/2004/09/goniobasis-and-elimia.html" target="_blank">28Sept04</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[23]</span></b> The controversy should have ended in 2011, when I
formally synonymized both <i>Goniobasis</i> and <i>Elimia</i> under <i>Pleurocera</i>, but it did
not. See:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Goodbye Goniobasis, Farewell Elimia [<a href="https://fwgna.blogspot.com/2011/03/goodbye-goniobasis-farewell-elimia.html" target="_blank">23Mar11</a>]</li></ul><o:p></o:p><p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-14127629680730243612023-02-07T11:12:00.005-05:002023-11-28T09:49:09.844-05:00New Clothes for The Emperor<p><span style="font-size: xx-small;">Editor’s Notes - If you’re just joining us, I apologize. This month’s blog builds from a series of eleven essays on the morphology, systematics, ecology and biogeography of the
planorbid genus Helisoma in the southeastern United States, stretching all the way back to 2004, as listed at
footnote <b><span style="color: #783f04;">[1]</span></b> below. No, you don’t have
to read that entire list, unless you are seriously interested in the
science. But the story below won’t make
any sense at all unless my two most recent essays, [<a href="https://fwgna.blogspot.com/2022/12/in-footsteps-of-comte-de-castlenau.html" target="_blank">6Dec22</a>] and [<a href="https://fwgna.blogspot.com/2023/01/the-helisoma-from-black-lagoon.html" target="_blank">5Jan23</a>], are fresh
in your mind. Oh, and all that anatomical
mishmash I reviewed two years ago, in [<a href="https://fwgna.blogspot.com/2021/02/the-emperor-non-child-and-not-short-duct.html" target="_blank">9Feb21</a>] will be super helpful for this
month’s essay, as well.</span></p><p><span style="font-size: xx-small;">This essay was subsequently published as: Dillon, R.T., Jr. (2023c) New Clothes for The Emperor. Pp 307 – 317<b> in</b> The Freshwater Gastropods of North America Volume 7, <i>Collected in Turn One, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank"> FWGNA Project</a>, Charleston, SC.</span></p><p>Both <i><a href="https://www.fwgna.org/species/planorbidae/h_scalaris_scalaris.html" target="_blank">Helisoma scalare</a></i> and <i><a href="https://www.fwgna.org/species/planorbidae/h_scalaris_duryi.html" target="_blank">Helisoma duryi</a></i> were described in
the 19th century from “The Everglades of Florida.” Both of their type localities were, however,
hundreds of miles north of the ecological region formally recognized as The
Everglades here in the 21st. And none
of the 20th century monographers who reviewed the planorbid gastropods in the
interim: Henry Pilsbry <b><span style="color: #783f04;">[2]</span></b> in 1934, F. C. Baker <b><span style="color: #783f04;">[3] </span></b>in 1945, or Bengt Hubendick
<b><span style="color: #783f04;">[4]</span></b> in 1955, had on his lab bench any live-collected topotypic material for
either nominal species. And as I merged
into the eastbound lanes of I-10 on Tuesday morning Feb 23, 2021, Tallahassee
in my rearview mirror, neither did I.</p><p>Both Pilsbry and Baker based their extensive and detailed
redescriptions of <i>Helisoma scalare</i> on a population of planorbids sampled from
“Lake Butler, Pinellas County.” In 1949
the Florida legislature changed the name of that particular body of water
to “Lake Tarpon” to mitigate confusion with another Lake Butler elsewhere in
The Sunshine State. And so, it was the coordinates of a boat launch in the John
Chestnut Park on the SE shore of Lake Tarpon, about 15 miles NW of Tampa, that
I had keyed into the GPS on my dash that cloudy February morning.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzdxaeZXZLO6gyG9OECNYne2YIAHETfieB0iUEXCUjGZ_MDoNuUvPumg6NEioZxaBioYEbw8Ua5aDuiM2DFzEhyC2QPUzhYmgziVwqbB31ftUGdP5UfpPHz-zQ4sOiBRQhRHEx-VcEXGqH-R4hfmsrDywgCFPtEc-B4LulXxVbxrJLQeFa29d9MhU2vA/s1830/H_scalaris-Tarpon.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1307" data-original-width="1830" height="229" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzdxaeZXZLO6gyG9OECNYne2YIAHETfieB0iUEXCUjGZ_MDoNuUvPumg6NEioZxaBioYEbw8Ua5aDuiM2DFzEhyC2QPUzhYmgziVwqbB31ftUGdP5UfpPHz-zQ4sOiBRQhRHEx-VcEXGqH-R4hfmsrDywgCFPtEc-B4LulXxVbxrJLQeFa29d9MhU2vA/s320/H_scalaris-Tarpon.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Helisoma scalare</i> from Lake Tarpon (nee Butler)</span></td></tr></tbody></table><p>And the body of water into which I launched my kayak some
four hours later, light drizzle notwithstanding, was a lovely lake of 2,500
acres, average depth 8 feet, clear and cool and blessed with an abundance of
macrophytic vegetation of all sorts: floating, emergent, and submerged. And the weeds of that last-listed category,
wafting in the gentle currents at depths of an arm’s length, were laden with
<i>Helisoma scalare</i> bearing shells of a most gratifyingly classic morphology, as
depicted in the figure above.</p><p>The situation in Lake Tarpon (nee Butler) turned out to be
quite reminiscent of that I described in The Everglades at the 40-Mile-Bend a
couple years ago [<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>]. The
flat-topped <i>Helisoma</i> seem to reach maximum abundance in the rooted-submerged
macrophytes in both places, especially inside beds of eel grass (<i>Vallisneria</i>). I also noted high densities around the roots
of emergent vegetation, such as cat tails (<i>Typha</i>). The snails do not seem to crawl up those
<i>Typha</i> stems to the surface under any circumstance, however. Their life habit appears exclusively benthic.</p><p>Indeed, during the couple hours I waded and kayaked around the
margins of Lake Tarpon, I developed the strong impression that no element of
the entire population of <i>Helisoma</i> dwelling therein ever, from its birth to its
death, rose to enfold an air pocket under its mantle, under any circumstance. This suggested to me that they would not
adapt well to warming or artificial enrichment, or to any perturbation that
might cause levels of dissolved oxygen to dip in their lovely lacustrine
environment. <i> Helisoma scalare</i>
populations seem to need large volumes of cool, clean, clear water.</p><p>Such a situation contrasts strikingly with the typical
habitat of <i>Helisoma duryi</i> in my experience, or (indeed) <i>Helisoma trivolvis</i>
throughout the remainder of North America.
Populations of more typically-planispiral planorbids are ordinarily
found grazing in floating macrophytes in warm, rich ponds or ditches, or on the
margins of riverine backwaters, almost always near the surface.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBB-EiMGl2SVqC33fK0ZuXGfC7OmCYzulB5jYJ-hSUDeEMurFspHuMZH8mt3AQ1cABh1WXCa4aZSo-TkY_BJevDwh9K1uObjFq4HjXjZGILuMGW1-C8RTmPeq325kO7PvTmj32BbC7hPNH911X56hvB9Ka25moOlVJLQZf8R78Fk5yFGCZEcmxJ_HEpw/s1381/L-Tarpon.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1036" data-original-width="1381" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiBB-EiMGl2SVqC33fK0ZuXGfC7OmCYzulB5jYJ-hSUDeEMurFspHuMZH8mt3AQ1cABh1WXCa4aZSo-TkY_BJevDwh9K1uObjFq4HjXjZGILuMGW1-C8RTmPeq325kO7PvTmj32BbC7hPNH911X56hvB9Ka25moOlVJLQZf8R78Fk5yFGCZEcmxJ_HEpw/s320/L-Tarpon.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Lake Tarpon</span></td></tr></tbody></table><p>And back wading in Lake Tarpon, I also developed the strong
impression that, setting aside their peculiar scalariform morphology, the
shells borne by this particular population of pulmonate snails were
exceptionally thick, heavy, and robust.
This seemed to imply some special adaptation for defense against
crushing predation. At this suggestion,
the schools of bream darting about in the clear waters around my feet seemed to
nod their heads in agreement.</p><p>The skies were growing leaden over the crystalline waters of
Lake Tarpon as I loaded my kayak back into my pickup and pushed the button on
my GPS unit for home. And the next
afternoon I dumped my big, fresh sample of <i>H. scalare</i> in an enamel pan on my lab bench
and pulled out the big samples of <i>H. duryi</i> I had collected in 2020. And I opened my well-thumbed copy of Pilsbry
1934 on the left side of my lab bench, and my much-beloved copy of Baker 1945
on the right. And to refresh everybody’s
memory:</p><p>In 1934 “The Elderly Emperor” gathered four previously
described species of Floridian planorbids into a new subgenus of <i>Helisoma</i> he
called <i>Seminolina</i>: <i>scalare</i> (Jay 1839), <i>duryi </i>(Wetherby 1879), and two fossil
species of Dall (1890), <i>conanti</i> and <i>disstoni</i>.
Under <i>Helisoma (Seminolina) duryi</i> he recognized six subspecies: the
typical <i>H. duryi duryi</i> (Wetherby), <i>intercalare</i> (Pilsbry 1887), <i>preglabratum</i>
(Marshall 1926), and three new ones: <i>normale</i>, <i>eudiscus</i>, and <i>seminole</i>. Together this set of six subspecific nomina
described a completely seamless progression from the compressed,
tightly-planispiral <i>eudiscus</i> to the typical, loosely-planispiral <i>duryi</i> to the flat-topped, scalariform <i>seminole</i>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1DblkdDj0y_YoWq-Y_TrU11vpvLeTB1l78QXm5AhuoFndAZT83ZG0jC_wKTBEpZnCav0K3HSD5V5YD0qaYwUuAlhxAkXxkLpGiH0a_8QunFGt5r81QbeVi8uPpChTcnxelZzG_AY6j7Wm5xPf6eZnsAQbv4TENpRa_QGeTbcspXs5BMdJAPGN6iSGcQ/s3190/Pilsbry-fig2.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3190" data-original-width="3025" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1DblkdDj0y_YoWq-Y_TrU11vpvLeTB1l78QXm5AhuoFndAZT83ZG0jC_wKTBEpZnCav0K3HSD5V5YD0qaYwUuAlhxAkXxkLpGiH0a_8QunFGt5r81QbeVi8uPpChTcnxelZzG_AY6j7Wm5xPf6eZnsAQbv4TENpRa_QGeTbcspXs5BMdJAPGN6iSGcQ/s320/Pilsbry-fig2.jpg" width="303" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Pilsbry <b><span style="color: #783f04;">[5]</span></b></span></td></tr></tbody></table><p>But to be clear.
Pilsbry did not subscribe to the modern convention that subspecies
demonstrate any sort of geographical isolation.
He wrote:</p><p></p><blockquote><span style="font-size: x-small;">“In a well-watered region of low relief, like Florida, no
barriers to the migration of these snails exist, so that the geographic limits
of such races are only vaguely defined. The shell characters are so variable
that with single shells or small series the identity may often be in doubt.”</span></blockquote><p></p><p>In the image below, clipped from Pilsbry’s Plate 7, the top
row of shells (5a – 5f) were all borne by a <i>Helisoma duryi</i> population sampled
from “near Lake Apopka,” the second row (6a – 6f) all from a population
inhabiting Lake Eustis (Lake Co.), and the third row (7a – 7e) all from the
Head of the Miami River. This entire set
of 17 shells he identified as varying subspecies of <i>Helisoma duryi</i>. There is no difference between shells 5e, 5f,
6e, 6f, and any of the shells I collected from Lake Tarpon.</p><p>So again, I ask. If
not the shell morphology, what exactly is the difference between <i>Helisoma duryi</i>
– particularly the subspecies that Pilsbry began calling <i>H. duryi seminole</i> in
1934 – and the earlier-described <i>H. scalare</i>?
The distinction that Henry Pilsbry drew in 1934 turned out to be
entirely anatomical. The <i>duryi/scalare</i>
situation is very closely analogous to the <i>duryi/trivolvis</i> situation we
reviewed at great length back on [<a href="https://fwgna.blogspot.com/2021/02/the-emperor-non-child-and-not-short-duct.html" target="_blank">9Feb21</a>], involving many of the same
anatomical features, and (indeed) the same illustrations of them. So to refresh everybody’s memory, again:</p><p>It was upon Henry Pilsbry’s head that rested the crown of
American Malacology, pretty much his entire career, from 1887 to 1957. Frank Collins Baker, more experienced as a
field biologist and more gifted as a scientist, studied under Pilsbry in 1889,
and labored in his shadow thereafter, predeceasing his mentor by 15 years. And to understand what I’m getting ready to
tell you about <i>scalare</i> and <i>duryi</i>, you need to understand the relationship
between Pilsbry and Baker. A bit of
familiarity with the reproductive plumbing of pulmonate gastropods will also be
helpful, but not necessary.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj4z5uydTvd8B2UZa_8rNKkEpjrVnxTsfZoh-zEVUnD1I8AoHfg_DEDfBucyfG_KzYL4RCjGXd9vxo8iaDLoNauKg7a53DQOg_PQ7m8w9bVbiwoO_hLqtfK9IxmLrcklFlNmIwI6vvg7nYXI8_oNPNHPEPb1xYpEiDza7Qx-2K_03-7VfB-C09QFsOYg/s517/pilsbry-seminole-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="348" data-original-width="517" height="215" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjj4z5uydTvd8B2UZa_8rNKkEpjrVnxTsfZoh-zEVUnD1I8AoHfg_DEDfBucyfG_KzYL4RCjGXd9vxo8iaDLoNauKg7a53DQOg_PQ7m8w9bVbiwoO_hLqtfK9IxmLrcklFlNmIwI6vvg7nYXI8_oNPNHPEPb1xYpEiDza7Qx-2K_03-7VfB-C09QFsOYg/s320/pilsbry-seminole-montage.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Pilsbry <b><span style="color: #783f04;">[2]</span></b> Plate 7.</span></td></tr></tbody></table><p>When not in use, pulmonate gastropods invert their penis –
turn it outside in – to make a bag with the business end inside. Figure <span style="color: red;">(A)</span> in the montage below shows the
structure that Pilsbry (1934) simply called the <i>Helisoma scalare</i> “penis,
unopened.” It’s an (upside down) sack,
with an opening in the bottom through which the penis everts for
copulation. The figure I’ve marked <span style="color: red;">(B)</span>
shows a <i>Helisoma scalare </i>penis sack opened, Pilsbry’s “V” standing for “verge,”
which is a polite name for the business end of the penis during
copulation. And the organ Pilsbry has
marked “pg” is the penial gland, which presumably supplies some sort of
lubrication during copulation, or stimulation, heaven knows.</p><p>So, to distinguish the two nominal species of the subgenus
<i>Seminolina</i>, <i>scalare</i> and <i>duryi</i>, Pilsbry focused exclusively upon differences he
perceived in the penial gland. In his
description of his new scalariform subspecies <i>H. duryi seminole</i>, he wrote:</p><p></p><blockquote><span style="font-size: x-small;">“I dissected specimens collected many years ago in Polk Co.,
Florida, by S. Hart Wright, and similar in shape to fig. 6d of Plate 7. The
bodies are brittle, and only the penis was examined <span style="color: red;">(figure C)</span>, cylindric, with
the upper sac divided off inside by a thin rather high ridge. The stout conic
verge projects into the lower sac. The penial gland is oblong with the<b> smooth
lateral borders folded </b>in the alcoholic specimens, as in figure <span style="color: red;">(C)</span>. This
structure is quite unlike that found in <i>H. scalare</i> <span style="color: red;">(B)</span>.”</span></blockquote><p></p><p>And to reinforce the distinction, here is what Pilsbry said
in his redescription of <i>H. scalare</i>:</p><p></p><blockquote><span style="font-size: x-small;">“In the specimens of <i>H. duryi seminole</i> opened, the penial
gland was found to differ [from <i>H. scalare</i>] in important details. It [the <i>duryi</i>
penial gland] has a broad oblong face directed toward the cavity, with the
<b>lateral borders infolded</b> in alcoholic specimens, as in figure <span style="color: red;">(C)</span>. The division
between upper and lower sacs of the penis is a single rather high thin ridge.
The stouter shape of the verge in <i>H. d. seminole </i>may be due to greater
contraction, as the specimens had evidently been killed in strong alcohol.”</span></blockquote><p></p><p>Now moving forward ten years. In addition to the three Pilsbry figures I
have reproduced below F. C. Baker’s (1945) figure of the same organ – less
artistic but more scientific <span style="color: red;">(D)</span>. Baker
did not execute separate drawings for <i>scalare</i> and <i>duryi</i>. This single figure was offered to represent
the entire subgenus <i>Seminolina</i>, including <i>scalare</i> and <i>duryi</i> of all subspecies.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhphgv0DWyF844itopsTRsYM4dFNP4-HkUaBGm4zN35cyKs7iN6bPtYhtZAe3R65nD5Bd0OcR2PUwRU8875MC9Dz5DNzXdd7vptJjod7mYjFFlqX4sQ_c9BZxJNjO7kDQ6Vq42NZ9iMb3Uh6UGgvbUIyH4Ckiix2Otj7ZOX9yRT58LgL_9_wTwzoWez2A/s1032/duryi&scalaris-penes.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="402" data-original-width="1032" height="156" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhphgv0DWyF844itopsTRsYM4dFNP4-HkUaBGm4zN35cyKs7iN6bPtYhtZAe3R65nD5Bd0OcR2PUwRU8875MC9Dz5DNzXdd7vptJjod7mYjFFlqX4sQ_c9BZxJNjO7kDQ6Vq42NZ9iMb3Uh6UGgvbUIyH4Ckiix2Otj7ZOX9yRT58LgL_9_wTwzoWez2A/w400-h156/duryi&scalaris-penes.jpg" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Penial complexes from Pilsbry <b><span style="color: #783f04;">[2]</span></b> and Baker <b><span style="color: #783f04;">[3]</span></b></span></td></tr></tbody></table><p>Baker dissected 35 individuals from the “Lake Butler” (now
L. Tarpon) population of <i>H. scalare</i>, and populations of <i>H. duryi</i> from seven
different sites, representing three subspecies.
Regarding the Lake Tarpon population, Baker was quick to pay homage to
the Elderly Emperor:</p><p></p><blockquote><span style="font-size: x-small;">“The genitalia of <i>Helisoma scalare</i> examined agree perfectly
with the figures published by Pilsbry 1934.”</span></blockquote><p></p><p>Turning to his <i>H. duryi</i> samples, Baker figured on his Plate
33 the “penial complexes” (Pilsbry’s “penis unopened”) from 12 different <i>H.
duryi</i> individuals dissected from four populations of three different
subspecies, all pushed, pulled, shrunk and extended into a myriad of diverse,
blobby profiles. And hidden among his
observations was this single-line bombshell, directly contradicting the only
distinction that Pilsbry had ever drawn between <i>scalare</i> and <i>duryi</i>:</p><p></p><blockquote><span style="font-size: x-small;"><b>“The penial gland in the <i>duryi</i> complex is of about the same
shape as that organ in <i>scalare</i>.”</b></span></blockquote><p></p><p>Poor Frank Collins Baker!
I can still feel the anguish seeping from page 132 of his planorbid
monograph, here 80 years later. The
character of the penial gland that Pilsbry called “lateral borders infolded” is
trivial at best, entirely artifactual if it ever existed. Baker couldn’t confirm it in a dozen<i> H. duryi</i>
sampled from four populations. But
neither could he risk offending his Emperor.
So, all he could do was to dissemble, which he did, five sentences
later:</p><p></p><blockquote><span style="font-size: x-small;">“The figures of the <i>duryi</i> complex agree with those by
Pilsbry (1934). As Pilsbry remarks on
page 36, the anatomical differences are sufficient to separate <i>scalare</i> from
<i>duryi</i> and its races.”</span></blockquote><p></p><p>The bottom line for us today is, however, that there is no
evidence of any morphological distinction whatsoever, shell or anatomical,
heritable or otherwise, let alone any evidence of reproductive isolation,
between the diverse planorbid populations found throughout Florida and around
the world conventionally identified as <i>Helisoma (Planorbella) duryi</i>, and the
earlier described planorbid populations of deeper, cooler and cleaner Floridian
waters identified as <i>Helisoma (Planorbella) scalare</i>. <b>Wetherby’s (1879) nomen <i>duryi</i> is a junior
synonym of Jay’s (1839) <i>scalaris</i> or <i>scalare</i> <span style="color: #783f04;">[7]</span>.</b></p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZ-5TyXcT8UuVXoPaBigPsRJw0GR-m_1JpXLyFVCxJGatEZbNc4ZpnI7jM6lYF-LqInj3QoVhOqAfjG3gxWVhdyW9wSjwNy-hqJ3MKdEhaPouTLkCC5uEljxwZbB7XhIy03_V0PaAqyIvBZwG3HWOhNUH9UHz7ib52ZGj2RupMf6UjlZlzvIhBxqgOPQ/s3507/Pilsbry-fix.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="3507" data-original-width="3325" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZ-5TyXcT8UuVXoPaBigPsRJw0GR-m_1JpXLyFVCxJGatEZbNc4ZpnI7jM6lYF-LqInj3QoVhOqAfjG3gxWVhdyW9wSjwNy-hqJ3MKdEhaPouTLkCC5uEljxwZbB7XhIy03_V0PaAqyIvBZwG3HWOhNUH9UHz7ib52ZGj2RupMf6UjlZlzvIhBxqgOPQ/s320/Pilsbry-fix.jpg" width="303" /></a></div>But let’s <b>save <i>duryi</i> at the subspecific level to describe
populations of <i>H. scalare</i> bearing planispiral shells,</b> shall we? I hasten to remind everybody, once again,
that the FWGNA has adopted the definition of the word subspecies in currency
since the birth of the modern synthesis: “populations of the same species in different
geographic locations with one or more distinguishing traits.” No additively heritable basis for the shell
morphological distinction between the typical scalariform morphology and the
planispiral <i>duryi</i> morphology is necessary, or implied <b><span style="color: #783f04;">[8]</span></b>.<p></p><p>And I also hasten to remind my readership that the “different
geographic locations” may differ at very small scales in freshwater
gastropods. See my essay of [<a href="https://fwgna.blogspot.com/2005/02/shell-morphology-current-and-substrate.html" target="_blank">18Feb05</a>]
for an example here in the Charleston area where populations of the <i>duryi</i>
subspecies and the typical subspecies are separated by only a few meters.</p><p>As we have seen, the most obvious correlation seems to be
with the habitat: scalariform populations inhabiting submerged macrophytes and
benthic substrates in large, permanent clearwater lakes and springs absent
contact with the surface, planispiral populations inhabiting emergent or
floating macrophytes on the margins of ponds, ditches and riverine
backwaters.</p><p>There is also a correlation with predator pressure: the
scalariform populations of clearwater lakes suffering more fish predation, the
planispiral populations more beset by invertebrate predators like crayfish and
leeches. And trematode parasites,
apparently. For completeness, here’s an
interesting observation from Baker, page 134:</p><p></p><blockquote><span style="font-size: x-small;">“The <i>Helisoma duryi</i> complex includes several races more or
less heavily infested with parasitic worms.
These include <i>normale, intercalare, eudiscus</i>, and <i>duryi</i>. Many specimens were so badly infested that
most of the organs, especially the genitalia, were completely obliterated. <i>Helisoma scalare</i> was the least affected.”</span></blockquote><p></p><p>In conclusion.
Nothing I have written in this essay is intended as a criticism of Henry
Pilsbry or (heaven forbid!) Frank Collins Baker, both of whose works stand
today at the pinnacle of classical American malacology <b><span style="color: #783f04;">[9]</span></b>. Pilsbry was The Emperor, and if in his
judgement some wrinkle or fold in some gland or tube confirmed the specific
status of some gastropod population somewhere, in late pre-modern systematic
biology, that settled it. Baker was a
courtier, following in retinue behind.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCNn-r07EqNXUT_QC5EJ1z7_uGH_Qyi2SLcUWWBbaM1zz28oKbo6zElvHoiwF4djSuzcSJkNe5a3-AWsYI3P2RHAtM_Lr8jIUAjjsPj8rfixCglRYVKCAhRbVn_rQ13kP9d0GET89HWTxjxnT3K2IBV2KFni4vebYH5Ii24O9jtM94Or_VIM2FvBWh2A/s819/sweeper.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="594" data-original-width="819" height="145" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCNn-r07EqNXUT_QC5EJ1z7_uGH_Qyi2SLcUWWBbaM1zz28oKbo6zElvHoiwF4djSuzcSJkNe5a3-AWsYI3P2RHAtM_Lr8jIUAjjsPj8rfixCglRYVKCAhRbVn_rQ13kP9d0GET89HWTxjxnT3K2IBV2KFni4vebYH5Ii24O9jtM94Or_VIM2FvBWh2A/w200-h145/sweeper.jpg" width="200" /></a></div><p>I’d like to imagine myself in the story as a small boy
watching the grand parade, naively observing that even if the margins of some
particular gland in some particular snail really were folded in the particular
fashion The Emperor decreed, naturally and not the result of some sort of
artifact, it just wouldn’t matter anyway.</p><p>But alas, The Emperor, his Retinue and his Grand Parade have
long, long passed, many years ago. And
I’m just sweeping up behind.</p><p><br /></p><p><u>Notes</u></p><p><b><span style="color: #783f04;">[1]</span></b> Here’s a complete list of all essays previously posted
on this blog relevant to the argument I am advancing this month:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Gigantic pulmonates [<a href="https://fwgna.blogspot.com/2004/11/gigantic-pulmonates.html" target="_blank">29Nov04</a>]</li><li>Shell morphology, current, and substrate [<a href="https://fwgna.blogspot.com/2005/02/shell-morphology-current-and-substrate.html" target="_blank">18Feb05</a>]</li><li>Juvenile Helisoma [<a href="https://fwgna.blogspot.com/2020/09/juvenile-helisoma.html" target="_blank">9Sept20</a>]</li><li>The Flat-topped Helisoma of The Everglades [<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>]</li><li>Foolish things with Helisoma duryi [<a href="https://fwgna.blogspot.com/2020/11/foolish-things-with-helisoma-duryi.html" target="_blank">9Nov20</a>]</li><li>The Emperor Speaks [<a href="https://fwgna.blogspot.com/2020/12/the-emperor-speaks.html" target="_blank">3Dec20</a>]</li><li>Collected in turn one [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>]</li><li>Dr. Henry A. Pilsbry was a jackass [<a href="https://fwgna.blogspot.com/2021/01/dr-henry-pilsbry-was-jackass.html" target="_blank">26Jan21</a>]</li><li>The Emperor, the Non-child, and the Not-short Duct [<a href="https://fwgna.blogspot.com/2021/02/the-emperor-non-child-and-not-short-duct.html" target="_blank">9Feb21</a>]</li><li>In the Footsteps of the Comte de Castelnau [<a href="https://fwgna.blogspot.com/2022/12/in-footsteps-of-comte-de-castlenau.html" target="_blank">6Dec22</a>]</li><li>The Helisoma from the Black Lagoon! [<a href="https://fwgna.blogspot.com/2023/01/the-helisoma-from-black-lagoon.html" target="_blank">5Jan23</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> Pilsbry, H. A. (1934) Review of the Planorbidae of
Florida, with notes on other members of the family. Proceedings of the Academy of Natural
Sciences of Philadelphia 86: 29 – 66.</p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Baker, F. C. (1945) The Molluscan Family Planorbidae.
University of Illinois Press, Urbana. 530 pp.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Hubendick, B. (1955) Phylogeny in the Planorbidae.
Trans. Zool. Soc. London 28: 453-542.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5] </span></b>This is quite possibly the most famous figure Pilsbry
ever published. It depicts the only
overtly evolutionary thought that ever flickered through The Elderly Emperor’s
mind, as far as I know. It was
reproduced on page 280 in Burch <b><span style="color: #783f04;">[6]</span></b>, and I dredged it up again for my <i>Helisoma</i>
essay of [<a href="https://fwgna.blogspot.com/2005/02/shell-morphology-current-and-substrate.html" target="_blank">18Feb05</a>].</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> This is a difficult work to cite. J. B. Burch's North American Freshwater
Snails was published in three different ways.
It was initially commissioned as an identification manual by the US EPA
and published by the agency in 1982. It
was also serially published in the journal Walkerana (1980, 1982, 1988) and
finally as stand-alone volume in 1989 (Malacological Publications, Hamburg,
MI).</p><p class="MsoNormal"><b><span style="color: #783f04;">[7] </span></b>Pilsbry re-spelled the feminine <i>scalaris</i> to the neuter
<i>scalare</i> to agree in gender with the neuter noun-construct <i>Helisoma</i>. His Imperial Majesty did not stoop to explain that fine
point of Latin grammar himself, however.
My good buddy Harry Lee was much more helpful.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> For a complete discussion of the subspecies concept as
adopted by the FWGNA project, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>What is a subspecies [<a href="https://fwgna.blogspot.com/2014/02/what-is-subspecies.html" target="_blank">4Feb14</a>]</li><li>What subspecies are not [<a href="https://fwgna.blogspot.com/2014/03/what-subspecies-are-not.html" target="_blank">5Mar14</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> Neither Pilsbry nor Baker was touched by the modern
synthesis, although I’d like to think that Baker would have been receptive, had
he survived beyond 1942. This makes the
1934 work of Calvin Goodrich <b><span style="color: #783f04;">[10]</span></b> all the more impressive, if you think about
it, am I right?</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> For an appreciation of Calvin Goodrich, see his brief
bio, then review his 1934 masterwork:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Legacy of Calvin Goodrich [<a href="https://fwgna.blogspot.com/2007/01/legacy-of-calvin-goodrich.html" target="_blank">23Jan07</a>]</li><li>CPP Diary: The spurious Lithasia of Caney Fork [<a href="https://fwgna.blogspot.com/2019/09/cpp-diary-spurious-lithasia-of-caney.html" target="_blank">4Sept19</a>]</li><li>Intrapopulation gene flow: Lithasia geniculata in the Duck
River [<a href="https://fwgna.blogspot.com/2021/12/intrapopulation-gene-flow-lithasia.html" target="_blank">7Dec21</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com4tag:blogger.com,1999:blog-1925453458905823877.post-71129957874602142512023-01-05T14:39:00.012-05:002023-11-28T09:44:42.496-05:00The Helisoma from the Black Lagoon!<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMEMFhH1QG5JihIvApg6HRQ9DPXdlPKcbgudY2MSO-hJFwJPP0X5xNQb7_0eyokPhjOIJanyaAk6XiV-nXWu3Io2NDQGRew90ubpZ5YHPkPnAw7iNSeGd-VgTBE6Wb3IjA7Ji58WSzsKwHDs2AUF7HDx-HqbnxdCnXkHZ5YVquiZxReWQgLWSBaWo4Cw/s719/scalaris-from-the-black-lagoon.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="719" data-original-width="605" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMEMFhH1QG5JihIvApg6HRQ9DPXdlPKcbgudY2MSO-hJFwJPP0X5xNQb7_0eyokPhjOIJanyaAk6XiV-nXWu3Io2NDQGRew90ubpZ5YHPkPnAw7iNSeGd-VgTBE6Wb3IjA7Ji58WSzsKwHDs2AUF7HDx-HqbnxdCnXkHZ5YVquiZxReWQgLWSBaWo4Cw/w168-h200/scalaris-from-the-black-lagoon.jpg" width="168" /></a></div><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023c) The Helisoma from the Black Lagoon! Pp 297 – 306 <b>in</b> The Freshwater Gastropods of North America Volume 7, <i>Collected in Turn One, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span><div><br /></div><div>Last month <b><span style="color: #783f04;">[1]</span></b> we toured all around Tallahassee and its
immediate environs with the Comte de Castelnau, trying to figure out where The
Count might have found a planorbid shell he gifted to John Clarkson Jay in
1838. Jay described that peculiar
flat-topped shell as <i><a href="https://www.fwgna.org/species/planorbidae/h_scalaris_scalaris.html" target="_blank">Paludina scalaris</a></i>, making wherever His Excellency might
have picked it up the type locality of a species widespread and common
throughout peninsular Florida. And
related in some very close way to <i><a href="https://www.fwgna.org/species/planorbidae/h_scalaris_duryi.html" target="_blank">Helisoma duryi</a></i> (Wetherby 1879), which has
been spread throughout the world.<p></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Well, as
the sun set on our first day of exploration, we had indeed found a couple
<i>Helisoma</i> populations, both of which (alas!) bore disappointingly planispiral
shells of dirt-common <i>duryi</i> morphology.<span style="mso-spacerun: yes;">
</span>To find a population bearing the flat-topped “scalariform” morphology,
we had resolved to venture further afield.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">South
and east of Tallahassee extend vast, marshy hinterlands drained by the St Marks
River, with its primary tributary the Wakulla.<span style="mso-spacerun: yes;">
</span>Although the formal appellation of “Everglades” has today been
reserved for regions much further south down the Florida peninsula, much of the St
Marks / Wakulla system might well have been colloquially referred to as
everglades by its nineteenth-century denizens <b><span style="color: #783f04;">[2]</span></b>.<span style="mso-spacerun: yes;"> </span>The hydraulics of the region are most unusual.<span style="mso-spacerun: yes;"> </span>Picking up our story once again, in the words of
Count Castelnau <b><span style="color: #783f04;">[3]</span></b>:</p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><blockquote><span style="font-size: x-small;">"This
river [the St. Marks] rises in Georgia, crosses Lake Mikasouky, sinks
underground and soon comes forth as a pond at Brookhaven."</span></blockquote><o:p></o:p><p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">That
area where the St. Marks “sinks underground” is today preserved in Natural
Bridge State Park, about 13 miles SE of Tallahassee <b><span style="color: red;">(G, map below)</span></b>. In March of 1865, less than thirty years
after The Count’s visit, a joint expeditionary force under the command of Maj.
Gen. John Newton landed at the St. Marks Lighthouse 10 miles downstream and
marched north intent on capturing the state capitol. Newton was repulsed at Natural Bridge by a
combined force of Florida cavalry, artillery, and militia, including cadets
from the institution of higher learning that would become Florida State
University. Tallahassee was the only
Confederate capitol east of the Mississippi River that did not fall to Yankees
during the war.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikK-XW-hEsFQiYPodE9D9UVQSCeGG7l1gbnPzbHNRpgoxeblwgnbSxIWWCkD0FOvXTiYpJ8d0DrFI_LeHXf5rcBfVUwk0gWWOUlWi6_Y4xtdMS-3OOV8ffHNwBSSEkbifghCjhQR9BMnzkGACLOUeeCiCavlf2j1aVK1JtME4sRlJ5Bd-7tJS4Jn6rKg/s640/Natural-Bridge-Monument.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="640" data-original-width="497" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikK-XW-hEsFQiYPodE9D9UVQSCeGG7l1gbnPzbHNRpgoxeblwgnbSxIWWCkD0FOvXTiYpJ8d0DrFI_LeHXf5rcBfVUwk0gWWOUlWi6_Y4xtdMS-3OOV8ffHNwBSSEkbifghCjhQR9BMnzkGACLOUeeCiCavlf2j1aVK1JtME4sRlJ5Bd-7tJS4Jn6rKg/w156-h200/Natural-Bridge-Monument.jpg" width="156" /></a></div>I found
The St Marks River forbiddingly black and deep as it enters Natural Bridge
State Park, with very little freshwater gastropod habitat in evidence. But in the nearby Natural Bridge Spring I
recorded eight species, including more <i>Helisoma</i> bearing
disappointingly-planispiral shells of the <i>duryi</i> type <b><span style="color: #783f04;">[4]</span></b>.<div> <p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Continuing
downstream on the St Marks River, The Count apparently visited the town of
Magnolia, founded by four brothers from the state of Maine as a cotton trading
port.<span style="mso-spacerun: yes;"> </span>The town is classified as
“extinct” by the state of Florida today, but even by 1837, it was apparently
struggling:</p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><blockquote><span style="font-size: x-small;">"Magnolia
is a little village, if this name may be given to two or three houses, situated
seventeen miles from the Gulf of Mexico on the St. Marks River; it was built in
1827. It is almost abandoned today because of fear of the Seminole Indians who
several times have committed massacres in the vicinity. The soil is fertile and
the banks of the river are charming."</span></blockquote><p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">The
historical footprint of Magnolia is approximately 1 mile north of the
present-day town of Newport, where US98 crosses the St. Marks River <b><span style="color: red;">(H)</span></b>.<span style="mso-spacerun: yes;"> </span>I couldn’t find any public access to the
river in Newport, but no decent freshwater gastropod habitat was visible from
the bridge in any case, so screw it.</p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">But now
for the highlight of our visits to Florida, both of the Count’s in 1837 and my
own in early 2021.<span style="mso-spacerun: yes;"> </span>About 13 miles due
south of Tallahassee is the aquatic wonderland of Wakulla Springs, “the largest
and deepest natural spring in the world <b><span style="color: #783f04;">[5]</span></b>.”<span style="mso-spacerun: yes;">
</span>Castelnau made his approach via water, rowing upstream from the town of
St. Marks “by great effort, through snags.”</p><blockquote>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><span style="font-size: x-small;"><span>"Our
little expedition left St. Marks at sunrise, and having gone around the point
where the old fort is, entered Wakulla River; it is at first very wide and on
its marshy shores there are a few scattered pines… </span><span>We had
to struggle against a current of about a league per hour; the shores are very
marshy and flooded, the river bed is covered with high grass which blocks the
passage; in some places very big bushy canes also increase the difficulty of
travel by water. We soon arrived among vast cypress groves whose trees are
grouped in the form of islands; everywhere fallen tree trunks blocked our way."</span></span></p></blockquote>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">I
launched my kayak into the Wakulla River at the Shadeville Road bridge <b><span style="color: red;">(I)</span></b> and
spent a lovely couple hours sampling the clear, cool, rich waters about three
miles downstream from the spring.<span style="mso-spacerun: yes;"> </span>I was
especially charmed by the big <i>Nerita reclivata</i> grazing across the surfaces of
the emergent <i>Sagittaria</i> grass beds, the first freshwater nerites I had ever seen in
the wild [<a href="https://www.fwgna.org/downloads/Wakulla-nerite.jpg" target="_blank">click to download</a> an action shot.]<o:p></o:p></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCwaBKctWleKbwghWI5eqPnMVImUBFClTKKwxINMrUxY2SK1wAyPbnRFsCgBxx7RgFtmB8VgLl8JwjTgpLr1aE_gsEdXXds1xcRt-sSj9-aWSIgpNYmTU6gSxIzfbGaJ2hiSJjAofiCo4CXMXQSggfLTGvkxZJie3BQ_kQZB443nxeyVqZkDiBzUfvWQ/s616/Tallahassee-stations-day2-trim.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="616" data-original-width="349" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhCwaBKctWleKbwghWI5eqPnMVImUBFClTKKwxINMrUxY2SK1wAyPbnRFsCgBxx7RgFtmB8VgLl8JwjTgpLr1aE_gsEdXXds1xcRt-sSj9-aWSIgpNYmTU6gSxIzfbGaJ2hiSJjAofiCo4CXMXQSggfLTGvkxZJie3BQ_kQZB443nxeyVqZkDiBzUfvWQ/s320/Tallahassee-stations-day2-trim.jpg" width="181" /></a></div><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">The
freshwater gastropod fauna was otherwise disappointing, however; a gigantic
population of grotesque <i><a href="https://www.fwgna.org/species/thiaridae/m_tuberculata.html" target="_blank">Melanoides tuberculata</a></i> outnumbering the native
<i>Pleurocera floridensis</i> about a zillion-to-one.
I found no living hydrobioids, indeed counting myself lucky to net up a
singleton <i>Notogillia</i> shell. As for
<i>Helisoma</i>, I was able to find exactly N = 2 in two hours of effort, both bearing
entirely unremarkable shells of planispiral morphology.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">And any
thoughts I might have entertained about kayaking upstream to the springhead
were dashed by a curtain of fencing hung across the entire width of the river
above the bridge, festooned with signage most uncordial.<span style="mso-spacerun: yes;"> </span>I loaded my kayak back into the truck and
completed my journey to Wakulla Springs in routine, 21st century fashion. </p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><blockquote><span style="font-size: x-small;">"The
spring is oval in form and three hundred feet wide. By taking soundings we
found that it was 76 feet deep. We were told however that in some places it was
100 feet deep; its water is wonderfully pure, and one can distinguish the
smallest objects that are on the bottom; Huge
flocks of birds came to give life to the scene, we noticed especially among
them beautiful herons of a dazzling white, pelicans with huge beaks provided
with a big pocket below them, numerous long legged water fowl, the pretty
Carolina parrakeet, etc., etc."</span></blockquote><p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">The
Count did not mention any human residents of the area at his visit in 1837, but
by 1875 enterprising locals were hosting guests and offering glass bottom boat
tours of the spring.<span style="mso-spacerun: yes;"> </span>Large scale
commercial development was delayed until the 1920s but kicked into high gear in
1934, when financier Edward Ball purchased all the acreage around the spring
and built a world-class resort hotel.<o:p></o:p></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Wakulla
Springs hosted US Army training maneuvers during World War II, including the
detonation of underwater explosives <b><span style="color: #783f04;">[6]</span></b>.
In the postwar heyday that followed, the springs served as the filming
location for at least one or two Tarzan movies, plus the 1954 cult classic,
“Creature From The Black Lagoon.” The
property was acquired by the Florida State Park system in 1986, who have
continued to run the hotel, beach, and boat tours very much in business.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuQnhX8nWw7_SmLwR861ks1Zk5-sgVz-hgt7NGMt80qcoMkjf-wJKGZRNcv2cXSRrbxCmyAU0IoQTUjogJ6xyucgJ6_2QGmLAY0xRhxINaZ1w1o8n_iQks6ggr4W-qWljTFpcH9wxWnXa6_nyWdrEdxpc_nu93Rm6G-hzjf9_rzc7zLGseH4xow0_d9w/s582/wakulla-springs.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="312" data-original-width="582" height="172" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuQnhX8nWw7_SmLwR861ks1Zk5-sgVz-hgt7NGMt80qcoMkjf-wJKGZRNcv2cXSRrbxCmyAU0IoQTUjogJ6xyucgJ6_2QGmLAY0xRhxINaZ1w1o8n_iQks6ggr4W-qWljTFpcH9wxWnXa6_nyWdrEdxpc_nu93Rm6G-hzjf9_rzc7zLGseH4xow0_d9w/s320/wakulla-springs.jpg" width="320" /></a></div><p></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Paying
my $4 admission price as I passed through the contact station, the ranger
glanced to the back of my pickup, noticed my kayak, and inquired, suspiciously,
“You’re not planning to launch that in here, are you?”<span style="mso-spacerun: yes;"> </span>“Gracious no!” I replied, “Such thoughts could not be further from my mind.”<span style="mso-spacerun: yes;"> </span>“Good,” he cautioned,
“The springs are a protected natural area.”<span style="mso-spacerun: yes;">
</span>Protected from biologists in kayaks, apparently, but not from glass
bottom motorboats or amphibious combat vehicles?</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">I had
planned a rather unconventional itinerary for my visit, stopping first near the
park entrance at the Sally Ward Spring Run <b><span style="color: red;">(J)</span></b>. It materializes that there is a
small, unfamous, and relatively ordinary spring in the cypress swamp upstream
from the main tourist attraction, feeding into the spectacular head of the
Wakulla River, within which the gill-faced Creatures lurk and upon which the
glass-bottomed boats motor.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">I found
the malacofauna of the spring run similar to that I had just sampled in the
main Wakulla River three miles downstream, although healthier <b><span style="color: #783f04;">[7]</span></b>. And once again, dwelling on the muddy margins
of the stream I found a sparse <i>Helisoma</i> population bearing shells of quite
unremarkable, planispiral morphology, no different from the <i>Helisoma</i> I had seen
at the Shadeville Rd bridge <b><span style="color: red;">(I)</span></b>, or at the Natural Bridge Spring earlier in the
morning<b><span style="color: red;"> (G)</span></b>, or indeed, on my explorations around Tallahassee the previous day.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCKuKC1wVR5ziXknC5Pr-1JObuSEjgDuP4bkdt8FTy6j1bhhWbJEkYFS6yDFLJV7KLzOcjPZZSDWSiOl2HXaT916Y_vkE5Fx1rykkAd7eWkPY_uSYKSDNnQEk4v9s-BykBWH1e7vOIH4jn5NUlm_61jJwsBm26-jxCDOvLPMGTJrtq03Ewr5QO7dtgcg/s3300/duryi-SallyWard.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3300" data-original-width="1856" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCKuKC1wVR5ziXknC5Pr-1JObuSEjgDuP4bkdt8FTy6j1bhhWbJEkYFS6yDFLJV7KLzOcjPZZSDWSiOl2HXaT916Y_vkE5Fx1rykkAd7eWkPY_uSYKSDNnQEk4v9s-BykBWH1e7vOIH4jn5NUlm_61jJwsBm26-jxCDOvLPMGTJrtq03Ewr5QO7dtgcg/w113-h200/duryi-SallyWard.jpg" width="113" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Sally Ward Spring</span></td></tr></tbody></table>Preliminary
scouting work complete, I parked my truck at the back of the main parking lot
for the tourist attraction and shucked off my hip waders so as not to attract
attention, selecting instead a pair of well-worn Converse that I didn’t mind
getting wet. I left my dipnet in the truck for the same reason, fearful that
any overt show of scientific activity might be interpreted as threatening to
the “protected natural area.” Then
putting my hands in my pockets, I strolled casually toward the waterfront <b><span style="color: red;">(K)</span></b>.</div><div><br />The
swimming beach was quiet on the brisk February morning of my visit and the tour
boats not running. But my attention was
called to a hive of activity around the diving platform shown at the far left
in the photo above. Joining the throng
on the top deck I was able to spy several manatees floating motionless in the
crystalline waters below.<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Oddly
enough, however, I found myself more enchanted by the rooted-submerged
macrophytic flora of the spring bottom than by the charismatic megafauna
floating over it.<span style="mso-spacerun: yes;"> </span>The waving jungles of
<i>Sagittaria</i> and <i>Vallisneria</i> interspersed with white sand bottom were simply
magical.<span style="mso-spacerun: yes;"> </span>Pretty little fish and minnows
nibbling about everywhere.<span style="mso-spacerun: yes;"> </span>A coot
paddled under my gaze, oblivious.<span style="mso-spacerun: yes;"> </span>Where
the hell are the snails, I thought to myself.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Where
the hell, indeed?<span style="mso-spacerun: yes;"> </span>I waded the entire
shoreline accessible from the developed side, including weedy margins and all
around the docks, to a depth of a foot or so, and did not find so much as a
crap <i>Physa</i>.<span style="mso-spacerun: yes;"> </span>Not a limpet on a leaf.<span style="mso-spacerun: yes;"> </span>I can’t remember the last time I was skunked
so thoroughly for so much effort.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Ah, but. Around the shorelines of the Wakulla Spring
pool one could hardly fail to note extensive deposits of relict shells. And common among those relicts were <i>Helisoma</i>
shells of the exact flat-top morphology demonstrated by the specimen presented
to John Clarkson Jay by Comte de Castelnau in 1837. <b> </b><b>I feel certain that Wakulla Springs is the
type locality of <i>Paludina scalaris </i>Jay 1839.</b>
For this conclusion I offer four lines of support:<o:p></o:p></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgN1oqCRQwikADlkzRD1lIwaZt7Apw53q9ARmsZ8CUmCupdYqyVQNRQfxvzjy8LhSYP8zSMjo8kYjhY0RP5TtFehNmGcXW6nVpCwepXikz44XTXDqyCHaHQ1dICNgvitXW2d0rh5M7MXAlsPWiAunAeinTH-pWJZIhHL-uUqbqL25TEz-NFwZufbNgDWw/s2400/scalaris-Wakulla.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2020" data-original-width="2400" height="269" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgN1oqCRQwikADlkzRD1lIwaZt7Apw53q9ARmsZ8CUmCupdYqyVQNRQfxvzjy8LhSYP8zSMjo8kYjhY0RP5TtFehNmGcXW6nVpCwepXikz44XTXDqyCHaHQ1dICNgvitXW2d0rh5M7MXAlsPWiAunAeinTH-pWJZIhHL-uUqbqL25TEz-NFwZufbNgDWw/s320/scalaris-Wakulla.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Beach at Wakulla Springs</span></td></tr></tbody></table><br /><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">First,
it seems quite possible that a living population of <i>Helisoma scalare</i> may
inhabit Wakulla Springs today, and I simply missed it. My readership will remember that the
population of flat-topped <i>Helisoma</i> I sampled at the Forty-mile Bend were
cowering in aquatic vegetation submerged several feet below the water surface
[<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>]. I was only able to collect
them by net, from a kayak. Absent either
of these tools in February of 2021, and stuck on the highly-disturbed south shore
of the spring, I was simply unable to sample the habitat adequately.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Second.<span style="mso-spacerun: yes;"> </span>Even if no flat-topped <i>Helisoma</i> population
inhabits Wakulla Spring today, it is certainly possible that a living
population existed in 1837 <span style="color: #783f04; font-weight: bold;">[8]</span><span>, subsequently extinguished by rampant commercial development, the glare of Kleig lights, and the underwater demolition necessary for successful amphibious assault</span>.<span style="mso-spacerun: yes;"> </span>Those
relict shells I collected perhaps a foot above the waterline of the springa pool
in early 2021 were not necessarily old.<span style="mso-spacerun: yes;">
</span>In addition to the <i>Helisoma</i>, the figure above depicts one<i> Pleurocera
floridensis</i> shell and two shells of <i>Melanoides tuberculata</i>, an exotic not recorded
from anywhere in Florida until 1966 <b><span style="color: #783f04;">[10]</span></b>.<span style="mso-spacerun: yes;">
</span>Might my chalky-white <i>Helisoma scalare</i> shell date but only to circa 1966,
as well?<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">Third,
even if no living population of <i>Helisoma</i> inhabited Wakulla Springs in 1837, the
type shell presented by the Comte de Castelnau to John Clarkson Jay in 1839 was
not live collected, either.<span style="mso-spacerun: yes;"> </span>Indeed, it
would seem more in keeping with the sensitivity of French nobility to pick up a
clean white shell from the beach than yank some greenish-brown booger from the
weeds, am I right? That is Jay's AMNH type specimen refigured under the Creature mask way up at top of the present essay, to refresh your memory.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">And
finally. I have been unable to find any
scalariform <i>Helisoma</i> anywhere else The Count might have visited in 1837. Of the ten other Castelnau sites I re-visited
in 2021, six yielded no <i>Helisoma</i> at all, and four yielded <i>Helisoma</i> bearing
unremarkable planispiral morphology.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;">All of
which brings us back, one more time, to the question I’ve been nibbling around
the edges of for nine essays now, and still not properly bit.<span style="mso-spacerun: yes;"> </span>What is the relationship between <i>Helisoma
scalare</i> and all those populations of large planorbids bearing unremarkable
planispiral shells, traditionally identified as <i>Helisoma duryi</i>?<span style="mso-spacerun: yes;"> </span>Next time we’ll answer that question.<span style="mso-spacerun: yes;"> </span>I promise.<o:p></o:p></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><u>Notes</u></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><br /></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[1]</span></b> If
you’re just joining us. This is the
ninth essay in a long-running series that had its roots in 2005, picked up
steam in 2020-21, and just resumed last month.
I won’t suggest that you go back and read the entire series unless you’re
seriously interested in the science. But
the present essay won’t make much sense unless you’ve read my 6Dec22 post, at
the minimum:</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><ul style="text-align: left;"><li>Shell
morphology, current, and substrate [<a href="https://fwgna.blogspot.com/2005/02/shell-morphology-current-and-substrate.html" target="_blank">18Feb05</a>]</li><li>Juvenile
Helisoma [<a href="https://fwgna.blogspot.com/2020/09/juvenile-helisoma.html" target="_blank">9Sept20</a>]</li><li>The Flat-topped Helisoma of The Everglades [<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>]</li><li>Foolish
things with Helisoma duryi [<a href="https://fwgna.blogspot.com/2020/11/foolish-things-with-helisoma-duryi.html" target="_blank">9Nov20</a>]</li><li>The Emperor Speaks [<a href="https://fwgna.blogspot.com/2020/12/the-emperor-speaks.html">3Dec20</a>]</li><li>Collected
in turn one [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>]</li><li>Dr.
Henry A. Pilsbry was a jackass [<a href="https://fwgna.blogspot.com/2021/01/dr-henry-pilsbry-was-jackass.html" target="_blank">26Jan21</a>]</li><li>In the
Footsteps of the Comte de Castelnau [<a href="https://fwgna.blogspot.com/2022/12/in-footsteps-of-comte-de-castlenau.html" target="_blank">6Dec22</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[2] </span></b>It
will be remembered from last month’s essay [<a href="https://fwgna.blogspot.com/2022/12/in-footsteps-of-comte-de-castlenau.html" target="_blank">6Dec22</a>] that Jay gave the type
locality of <i>Paludina scalaris</i> as “The Everglades of Florida.” And it will also be remembered from [<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>]
that regions around Tallahassee do not qualify as “Everglades” today.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[3]</span></b> This
month’s Castelnau quotes are extracted from:<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><ul style="text-align: left;"><li>Castelnau,
F., A.R. Seymour and M.F. Boyd (1948) Essay on Middle Florida, 1837 –
1838.<span style="mso-spacerun: yes;"> </span>The Florida Historical Quarterly
26(3): 199 – 255.</li></ul><o:p></o:p><p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[4]</span></b> The
freshwater gastropod fauna of Natural Bridge Spring: <i>Viviparus goodrichi</i>, <i>Pleurocera
floridensis</i>, <i>Spilochlamys conica </i>(topotypic!), <i>Amnicola limosa</i>, <i>Physa
carolinae</i>,<i> Laevapex fuscus</i>, <i>Ferrissia fragilis</i>, and the planispiral <i>Helisoma</i>.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[5]</span></b> Here
I’m quoting wakullasprings.org.<span style="mso-spacerun: yes;"> </span>They did
not share any data on the millions of other springs they must have measured
worldwide to arrive at their conclusion.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[6]</span></b> US
Army training video, from the State Library and Archives of Florida:<o:p></o:p></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><a href="https://www.floridamemory.com/items/show/296311" target="_blank">Wakulla Springs Military Training and Underwater Explosions</a></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;"><br /></span></b></p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[7]</span></b> The
Sally Ward Spring Run malacofauna is dominated by large populations of
<i>Pleurocera floridensis</i> and <i>Spilochlamys conica</i>, with <i>Melanoides </i>nowhere in
evidence.<span style="mso-spacerun: yes;"> </span>Both <i>Ferrissia rivularis</i> and<i>
Laevapex</i> cling to the macrophytes blades, with planispiral <i>Helisoma</i> and <i>Physa
carolinae</i> populations grazing sparsely at the stream edges. Scrappy evidence of <i>Viviparus</i> &
<i>Campeloma</i>.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[8]</span></b> My
search of the worldwide idigbio database <b><span style="color: #783f04;">[9] </span></b>for Planorbidae + Wakulla returned
a single record in the University of Florida Museum that might be of interest:
UF4855, collected from Wakulla Springs by J. Richardson in 1938.<span style="mso-spacerun: yes;"> </span>That lot, identified as “<i>Planorbella
duryi,</i>” demonstrates vanilla planispiral shell morphology, alas. I thank Roger Portell for his help with this question.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[9]</span></b> For
more about the IdigBio internet resource, see:</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"></p><ul style="text-align: left;"><li>20 Years of Progress in the Museums [<a href="https://fwgna.blogspot.com/2019/05/20-years-of-progress-in-museums.html" target="_blank">22May19</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><b><span style="color: #783f04;">[10]</span></b>
Clench, W.J. (1969) <i>Melanoides tuberculata</i> (Muller) in Florida.<span style="mso-spacerun: yes;"> </span>Nautilus 83: 72.</p><p class="MsoNormal" style="margin-bottom: 0in; margin-top: 0in; mso-add-space: auto; mso-margin-bottom-alt: 8.0pt; mso-margin-top-alt: 0in;"><o:p></o:p></p></div></div>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-11540702663733781812022-12-06T14:33:00.008-05:002023-11-28T09:40:10.215-05:00In the Footsteps of the Comte de Castelnau<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023c) In the Footsteps of the Comte de Castelnau. Pp 287 – 296 <b>in </b>The Freshwater Gastropods of North America Volume 7, <i>Collected in Turn One, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Way back in September of 2020 I concluded a mundane essay
about juvenile shell morphology with the following deceptively difficult
question: “<b>What, exactly, are <i>Helisoma scalare</i> and <i>Helisoma duryi</i>?</b>”</p><p>Over the four months and five essays that followed <span style="color: #783f04;"><b>[1]</b></span>, we
were able to establish that both taxa are big Floridian planorbids, sometimes
assigned to the genus “<i>Planorbella</i>” for no reason whatsoever [<a href="https://fwgna.blogspot.com/2020/09/juvenile-helisoma.html" target="_blank">9Sept20</a>], set
aside in a subgenus <i>Seminolina</i> by Henry Pilsbry <b><span style="color: #783f04;">[2]</span></b> in 1934 [<a href="https://fwgna.blogspot.com/2020/12/the-emperor-speaks.html" target="_blank">3Dec20</a>]. The difference between the two nominal
species lies in the shell coiling, <i><a href="https://www.fwgna.org/species/planorbidae/h_scalaris_scalaris.html" target="_blank">Helisoma scalare</a></i> being distinguished by a
peculiar flat-topped “scalariform” morphology.
<a href="https://www.fwgna.org/species/planorbidae/h_scalaris_duryi.html"><i>Helisoma duryi</i></a>, on the other hand, usually bears shells of the typical
planispiral type, so typical, in fact, that they are often very difficult to
distinguish from those borne by dirt-common <a href="https://www.fwgna.org/species/planorbidae/h_trivolvis.html" target="_blank"><i>Helisoma trivolvis</i></a> populations
widespread across the rest of North America [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>].</p><p>Ultimately, however, I only answered half of the question I
posed in September of 2020. Across the
six total essays I posted on the subject, I spent 50% of my time obsessing
about <i>Helisoma duryi</i>, focusing especially on their protean variability in shell
morphology, “short, fat, tall, skinny, and all over the place” [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>]. Then I spent 30% of my time obsessing about
<i>Helisoma trivolvis</i> and 20% of my time obsessing about Henry Pilsbry [<a href="https://fwgna.blogspot.com/2021/01/dr-henry-pilsbry-was-jackass.html" target="_blank">26Jan21</a>], never
really touching on <i>Helisoma scalare </i>at all.
So, this month let’s back up and get a fresh start at the <i>scalare</i> half
of the question, shall we?</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjP2V2X97IzdCfoJRH563vQjGNUD7SPfpz0ZBX1vD0pppw1j4nFmbtW-bGqWS_tSnA4HziEvhz_zScjYBREotS6sNEeJtmUCqbMiHlAzYupxOD97_VBpkS4dhn-aJk3remzNiQfcu94l4qJrF7UIGEmALc23JZK4e3IxVtmWz2xA5lu-YYVntjhj0bbJg/s939/Paludina_scalaris_AMNH56111.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="939" data-original-width="774" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjP2V2X97IzdCfoJRH563vQjGNUD7SPfpz0ZBX1vD0pppw1j4nFmbtW-bGqWS_tSnA4HziEvhz_zScjYBREotS6sNEeJtmUCqbMiHlAzYupxOD97_VBpkS4dhn-aJk3remzNiQfcu94l4qJrF7UIGEmALc23JZK4e3IxVtmWz2xA5lu-YYVntjhj0bbJg/w165-h200/Paludina_scalaris_AMNH56111.jpg" width="165" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>P. scalaris</i>, holotype <b><span style="color: #783f04;">[4]</span></b></span></td></tr></tbody></table>John Clarkson Jay (1808 – 1891) was the grandson of Founding
Father John Jay, the first chief justice of the United States and co-author of
The Federalist Papers. I gather that by
the 19th century the Jay family had acquired substantial means. John Clarkson was trained as a physician, but
apparently had enough liquid capital and leisure time to amass what was
reputedly “the most complete and valuable collection of shells in the United
States.” He published catalogues of his
shell collection in several editions 1835 – 1852, to which he appended
“descriptions of new or rare species.”
And it was in John Clarkson Jay’s third edition of 1839 <b><span style="color: #783f04;">[3]</span></b> that the
world was first introduced to “<i>Paludina scalaris</i>, Nobis. Habitat, Everglades of Florida.” After a one-sentence description of the
shell, Jay wrote, “It was presented to me by Count Castelneau.”<p></p><p class="MsoNormal">Jay’s holotype (AMNH 56111) is still held by the American
Museum of Natural History today <b><span style="color: #783f04;">[4]</span></b>, looking just as dramatically flat-topped
as Jay figured it in 1839. Jay’s nomen
“<i>scalaris</i>” or <i>scalare </i><b><span style="color: #783f04;">[5]</span></b> is the sixth oldest nomen applied to any of the large <b><span style="color: #783f04;">[6]</span></b> North
American planorbids, after <i><a href="https://www.fwgna.org/species/planorbidae/h_trivolvis.html" target="_blank">trivolvis</a>, glabratus</i> <b><span style="color: #783f04;">[7]</span></b>, <i><a href="https://www.fwgna.org/species/planorbidae/h_campanulatum.html" target="_blank">campanulata</a>, corpulentum</i>
and <i><a href="https://www.fwgna.org/species/planorbidae/h_anceps.html" target="_blank">anceps</a></i>.</p><p class="MsoNormal">But if there is one lesson I have learned over my many
months, indeed years, of struggling with the taxonomy of Florida freshwater
gastropods, it is that “The Everglades” is a big place. In our essay of [<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>] we learned that the
Everglades Ecoregion, as formally defined by the Feds, extends over all or part
of 18 South Florida counties, some 7,800 square miles. And in our essay of [<a href="https://fwgna.blogspot.com/2020/12/the-emperor-speaks.html" target="_blank">3Dec20</a>] we learned that
when Charles Dury told Albert Wetherby that he collected a sample of
planorbids in “The Everglades of Florida” in 1879, he meant in Volusia County,
a couple hundred miles north of anyplace that the Feds would call Everglades
today. What was “The Everglades” to a
French Count in 1839?</p><p class="MsoNormal">Fortunately, Henry Pilsbry left us a very helpful clue in
1934, just as he did with Wetherby’s <i>duryi</i>.
Quoting the Elderly Emperor verbatim <b><span style="color: #783f04;">[2]</span></b>:</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">“Jay's locality was ‘Everglades of Florida, presented to me
by Count Castelneau;’ that is, le Comte Franqois (or Francis) de Castelnau, who
travelled in the southeastern states in the thirties and early forties. He
published several papers in Bull. de la Soc. de Giographie, 1839-1842, in the
last (vol. 18, p. 252) alluding to his work on Florida, which I have been
unable to find in Philadelphia libraries. Probably the type locality can be
recovered by looking up Castelnau's itinerary in this book.”</span></blockquote><p></p><p class="MsoNormal">So here in the 21st century, Count Castelnau’s papers <b><span style="color: #783f04;">[8]</span></b>
are much easier to get hold of than they were in 1934. And even better, in 1948 a University of
Florida historian named Arthur R. Seymour translated Castelnau’s work into
English and republished it in The Florida Historical
Quarterly <b><span style="color: #783f04;">[9]</span></b>. And it materializes that
when Castelnau said “The Everglades,” he meant the Florida panhandle, somewhere
around Tallahassee.</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjkjOsGMjC3wp9mk5p8OIAhrvYxZPdI5te92IMwMnlsY3h4DqIBDTAo5ualz8G1B_Gu31Z6i6uF79hVZfdpEkTn96k4-jo49Dl7LO2gU0qplw0-dLVulz24bMlOTRdRRzEWndoYW82FJY8LhA-dvGyi-PeosIsi67_i260F04AlDb4jdohm7qh5NQUwrg/s483/Tallahassee-stations-day1.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="326" data-original-width="483" height="216" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjkjOsGMjC3wp9mk5p8OIAhrvYxZPdI5te92IMwMnlsY3h4DqIBDTAo5ualz8G1B_Gu31Z6i6uF79hVZfdpEkTn96k4-jo49Dl7LO2gU0qplw0-dLVulz24bMlOTRdRRzEWndoYW82FJY8LhA-dvGyi-PeosIsi67_i260F04AlDb4jdohm7qh5NQUwrg/s320/Tallahassee-stations-day1.jpg" width="320" /></a></div><p class="MsoNormal">Castlenau left Charleston, my hometown, in mid-November
1837, travelling first by rail to Augusta, then on “a very narrow and
detestable road” through the heart of Georgia.
His most interesting adventure southbound took place in the “ramshackle”
<b><span style="color: #783f04;">[10]</span></b> village of Bainbridge, where “about one hundred Chattahoutchi Indians, who
are allies of the whites, arrived bringing with them about sixty hostile Creeks
or Muscogis.” The Count was invited to
join the Chattahoutchis for “an entire night of dancing, drinking and
shouting.”</p><p class="MsoNormal">The Count arrived in Tallahassee after two weeks on the
trail, exploring about the vicinity until mid-March of 1838, leaving us vivid
accounts (and not a few interesting illustrations) of the small town and its
environs, before returning to Charleston by way of steamer up the Apalachicola/
Chattahoochee River. But alas, at no
time in any of his writings did he address the most important subject, the
snails he encountered along the way.</p><p class="MsoNormal">And so it came to pass that in February of 2021 I pointed my
trusty <b><span style="color: #783f04;">[11]</span></b> Mazda pickup south on I-95, Arthur Seymour’s translation of
Castelnau’s travelogue on the passenger seat, outward bound on yet another
planorbid-themed adventure. My plan was
to visit every body of water mentioned by The Count in his Florida explorations,
or at least representatives thereof, searching for a topotypic population of
<i>Helisoma scalare</i> (Jay 1839). In the
account that follows, I have interleaved quotes from Castelnau’s travels with
notes from my own fieldbook.</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">We passed over the Oclockone [Ochlockonee] River and the
Little River whose banks are delightful, then finding again pine woods we
reached in the evening Tallahassee, the end of our [outbound] trip.</span></blockquote><p></p>
<p class="MsoNormal">The Ochlockonee is what I would call (from my Carolina
Lowcountry perspective) a typical blackwater river.<span style="mso-spacerun: yes;"> </span>I launched my kayak at the boat ramp under
the US90 bridge <b><span style="color: red;">(A)</span></b> and paddled upstream around the bend and could find very
little habitat for freshwater gastropods of any sort – no submerged or floating
vegetation, indeed almost no vegetation at the margins.</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">Numerous springs exist in the neighborhood and from one of
them comes a pretty stream of water that after having wound around the eastern
part of the city [Tallahassee] runs into the forest and forms a charming
waterfall about sixteen feet high; it runs then into a ravine hollowed out of
limestone and disappears underground quarter of a mile farther.</span></blockquote><p></p><p class="MsoNormal">It is not uncommon in this part of the world for cities to
have been founded around notable springs.
Huntsville and Tuscumbia, Alabama, come to mind in this regard. In both of those cases, city fathers have set
aside parkland in the heart of the modern city and added all manner of
improvements to the springs, sometimes (in some cases, maybe) preserving some
ghost of the native macrobenthos in the process. Alas, the greatest disappointment of my
fieldtrip came early, as I arrived at Tallahassee’s midtown “Cascades Park”
<b><span style="color: red;">(B)</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsi_t0hzeG9WGMyAD-404bbWlnvzhiV3a_B48uRbTBEfUeKsVoI5IFPE_NiL5Jemfy8S_6xDj23-oGdNz_rD-PsxxXD2uefbTLpYGyQMp6Ryu5paUGjPQBoLjfEj_7dNNLP7dS2sqCx-uhg6bQ2aFV5itk2ARs2ZbHE40LYVK8qasIWvbk3755o-hSRg/s1600/capital-cascades-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="800" data-original-width="1600" height="160" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsi_t0hzeG9WGMyAD-404bbWlnvzhiV3a_B48uRbTBEfUeKsVoI5IFPE_NiL5Jemfy8S_6xDj23-oGdNz_rD-PsxxXD2uefbTLpYGyQMp6Ryu5paUGjPQBoLjfEj_7dNNLP7dS2sqCx-uhg6bQ2aFV5itk2ARs2ZbHE40LYVK8qasIWvbk3755o-hSRg/w320-h160/capital-cascades-montage.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Cascades Park</span></td></tr></tbody></table><p class="MsoNormal">The montage above shows the modern park, with Castelnau’s
original 1837 figure in the upper right corner.
Notice the landscaping beds around the modern spring run, specifically
designed to discourage park visitors from approaching the water. Little signs have been placed at the front of
those beds, warning us (and our pets) not to enter the “stormwater.” And alas, that is indeed a stormwater sewer
at red arrow in photo below, the water emanating from which bears a dark,
suspiciously-olive color. I spent about
10 – 15 minutes poking around the water in desultory manner, picking up <i>Physa</i>,
and moved on.</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">To the east of this town extend the lands offered by the
government of the United States to General Lafayette in which is a pretty lake
that bears his name. No words can convey the beauty of these sheets of water
which scattered in great numbers in the midst of virgin forests in Middle
Florida; they are filled with fish of many sorts and their surface is
everywhere enlivened by clouds of aquatic birds, above which flies constantly
the bald eagle. Among the denizens of these lakes we must mention the soft
shelled turtles, as well as the alligators that are abundant there; these last
reach ordinarily length of twelve feet, and although little to be feared, by
their repulsive aspect they inspire terror in persons not accustomed to seeing
them.</span></blockquote><p></p><p class="MsoNormal">The Federal Government did indeed grant the Marquis de
Lafayette a 36-square-mile tract east of Tallahassee in 1824, in gratitude for
his military service to our young republic.
Lafayette never visited, however, and the entire grant had been sold off
piecemeal by 1855. The Lake Lafayette to
which Castelnau referred was divided into three sections with dikes, its
central section dredged for recreational use, and given the odd name “Piney Z”
Lake, in honor of a nearby plantation.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipw7snhZabKDehfMlHpTKnWnn984KLZtAUOint_300TWEMek1PybvgzvIcDBW-hYLZrlUkdruLAYyrwNmTwv2NfmTNwv2pr7GXXEC87VPe6hDCeiTCim1DMeseHJTP2uoX1PxnpGLO-vYeQ0Zl3J9TJJkEazpME7jL8pImmmhDXNrnejPRgq5RFD3iiA/s640/Lake-Lafayette.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="480" data-original-width="640" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipw7snhZabKDehfMlHpTKnWnn984KLZtAUOint_300TWEMek1PybvgzvIcDBW-hYLZrlUkdruLAYyrwNmTwv2NfmTNwv2pr7GXXEC87VPe6hDCeiTCim1DMeseHJTP2uoX1PxnpGLO-vYeQ0Zl3J9TJJkEazpME7jL8pImmmhDXNrnejPRgq5RFD3iiA/w320-h240/Lake-Lafayette.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Lower Lake Lafayette</span></td></tr></tbody></table><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">I visited both the central Piney Z Lake <b><span style="color: red;">(C)</span></b> and Lower Lake
Lafayette <b><span style="color: red;">(D)</span></b> at the town of Chaires.
The former was warm and trashy, and hosted but <i>Physa</i> and <i>Pomacea
maculata</i>. I had great hope for the
latter, however, which I found to be a Lake in Name Only (“LINO”), choked with
aquatic vegetation of all sorts. Indeed,
I enjoyed one of my prettiest paddles in recent memory, spoiled only by the
thunderstorm evident on the horizon of the photo above. And the malacofauna, which comprised nothing
but <i>Physa</i> and <i>Pomacea</i>, again.</p><p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">Lake Jackson is situated a league and a half [north] from
Tallahassee. According to the Indians, its water gushed forth suddenly from
under the ground, covering a vast cultivated plain. It is certain that trees
are still to be seen there, and that when the water is low Indian trails may be
noticed.</span></blockquote><p></p><p class="MsoNormal">The hydraulics of Lake Jackson are indeed strange. The water level appeared at least ten feet
below bank full on the morning I visited at site <b><span style="color: red;">(E)</span></b>, boat ramps high and
dry. I asked a local angler if this
little patch of Florida might be suffering a drought, even as rainstorms daily
drenched the remainder of the Sunshine State, coast to coast. He replied in the negative, explaining that
the Lake has a small “closed basin,” and had gone entirely dry on several occasions
in his lifetime. I thought (to myself)
that a closed basin might rather lead one to expect high water in times as diluvian as
those we were currently experiencing.</p><p class="MsoNormal"></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK1wLS8QZ-FhLiAgjmwhJHdtBfyffGI2Ne47nvibLTd_lxN0XTvVPeRQFoeXrCbcOtrsfcoFypu6ysNmzCiUGVrPT5-SVtgyonNtULDF7Ka0Dhyf3tbEiyUGqmKCST3wpAj7cP6LJUyuQH0ERzNg3X2Q4n9SBFeTwqoWJofpQasEz0lcH-0seGLcauYw/s3300/duryi-munson.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3300" data-original-width="1538" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjK1wLS8QZ-FhLiAgjmwhJHdtBfyffGI2Ne47nvibLTd_lxN0XTvVPeRQFoeXrCbcOtrsfcoFypu6ysNmzCiUGVrPT5-SVtgyonNtULDF7Ka0Dhyf3tbEiyUGqmKCST3wpAj7cP6LJUyuQH0ERzNg3X2Q4n9SBFeTwqoWJofpQasEz0lcH-0seGLcauYw/w149-h320/duryi-munson.jpg" width="149" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Lake Munson</span></td></tr></tbody></table>In light of this intelligence, I suppose my readership will
not be surprised to learn that the malacofauna of Lake Jackson
depauperate. In addition to the trash
<i>Pomacea</i> I did find exactly N = 1 juvenile <i>Helisoma</i>. Which I hoped, upon my departure, that I
would not be forced to return and augment.<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">A great number of lakes or ponds are scattered to the south
of Tallahassee. All these lakes are surrounded by dense woods, which are
scattered some fine cotton and sugar plantations. Most of them seem to be
sinking leaving on their shores a great deal of fertile land. are often almost
entirely covered with rushes and plants. In their water are found great numbers
water serpents (mocassins), soft-shelled turtles, gators, among which swim
large flocks of aquatic their shores are crowded with bands of deer and many
white headed eagles soar over them or the oaks and the immense magnolias that
are shores.</span></blockquote><p></p><p class="MsoNormal">Lake Munson is a good representative of a “lake scattered to
the south of Tallahassee.” I paddled
around its west edge to no effect. But
at the outlet dam <b><span style="color: red;">(F)</span></b>, I was pleased to discover a healthy population of
<i>Helisoma</i>. I was simultaneously
disappointed, however, by the typical, planispiral shells they bore upon their
backs. None, alas, demonstrated the
“scalariform” shell morphology that made John Clarkson Jay’s <i>Paludina scalaris</i>
so distinctive.</p><p class="MsoNormal">As the sun set on a long, wet day touring the diverse
rivers, springs, lakes and ponds of Tallahassee and vicinity, I admit to
experiencing a bit of frustration. True,
I had found a couple scrappy populations of <i>Helisoma</i>. But none bore shells even remotely matching
Jay’s 1839 type specimen in the collection of the American Museum way up in New
York City. Were my hopes to be
blighted? Stay tuned!</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimICIuo_1vM2NNRqDmcexZe02PVm9ttE-eGIRyxxKrMxHxlEJzZQHIGm0wyZahrWT4AIL165UnCVkaQDeT4yvcWfXeSolA5HQQmeBvgiIAiyHVSkajCFGiILVM99mGYwQqeXPTUDfVmXvCmQy6vxKKARY-NV10xtyTYH4ZbGouEVT7scnyjqTuO42Ojw/s640/Lake-Munson.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="480" data-original-width="640" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEimICIuo_1vM2NNRqDmcexZe02PVm9ttE-eGIRyxxKrMxHxlEJzZQHIGm0wyZahrWT4AIL165UnCVkaQDeT4yvcWfXeSolA5HQQmeBvgiIAiyHVSkajCFGiILVM99mGYwQqeXPTUDfVmXvCmQy6vxKKARY-NV10xtyTYH4ZbGouEVT7scnyjqTuO42Ojw/w320-h240/Lake-Munson.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Lake Munson at the outlet</span></td></tr></tbody></table><br /><p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Here is my complete series on <i>Helisoma duryi</i> and the
flat-topped <i>Helisoma</i> of Florida to date:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Juvenile Helisoma [<a href="https://fwgna.blogspot.com/2020/09/juvenile-helisoma.html" target="_blank">9Sept20</a>]</li><li>The flat-topped Helisoma of The Everglades [<a href="https://fwgna.blogspot.com/2020/10/the-flat-topped-helisoma-of-everglades.html" target="_blank">5Oct20</a>]</li><li>Foolish things with Helisoma duryi [<a href="https://fwgna.blogspot.com/2020/11/foolish-things-with-helisoma-duryi.html" target="_blank">9Nov20</a>]</li><li>The emperor speaks [<a href="https://fwgna.blogspot.com/2020/12/the-emperor-speaks.html" target="_blank">3Dec20</a>]</li><li>Collected in turn one [<a href="https://fwgna.blogspot.com/2021/01/collected-in-turn-one.html" target="_blank">5Jan21</a>]</li><li>Dr. Henry A. Pilsbry was a jackass [<a href="https://fwgna.blogspot.com/2021/01/dr-henry-pilsbry-was-jackass.html" target="_blank">26Jan21</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> Pilsbry, H. A. (1934) Review of the Planorbidae of Florida, with notes on other members of the family. Proceedings of the Academy of Natural Sciences of Philadelphia 86: 29 – 66.</p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Jay, J.C. (1839)
A catalogue of the shells, arranged according to the Lamarckian system;
together with descriptions of rare species, contained in the collection of John
C. Jay, M.D. Third Edition. Wiley & Putnam, New York.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> I thank Ms. Lily Berniker of the AMNH for her prompt and
courteous attention to my request for this photograph.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Pilsbry <b><span style="color: #783f04;">[2]</span></b> re-spelled Jay's (feminine) <i>scalaris</i> to the neuter <i>scalare</i> to agree with the gender of the neuter noun construct <i>Helisoma</i>. I thank my good buddy Harry Lee for this insight.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Pilsbry divided all the North American Planorbidae into
two subsections, the large ones and the not-large ones <b><span style="color: #783f04;">[5]</span></b>. John Clarkson Jay’s <i>scalaris</i> is the sixth oldest
name for a large one. There are also
five older names for not-large North American planorbids, which do not concern
us here, but for the record: <i>parvus, deflectus, crista, armigera</i>, and <i>exacuous</i>.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Thomas Say gave the type locality for his (1818)
<i>Planorbis glabratus</i> as “Charleston, South Carolina.” Pilsbry questioned that locality, but I believe it. We'll come back to this subject in a couple months.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Here are the originals:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Castelnau, F. (1839) Note sur la Source de la Rivière de
Wakulla dans la Floride. Bulletin de la Société de Géographie 11 (2): 242 –
247.</li><li>Castelnau, F. (1842) Vues et Souvenirs de l’Amérique du
Nord. Paris.</li><li>Castelnau, F. (1842) Note de deux Itinéraries de Charleston
à Tallahassée.<span style="mso-spacerun: yes;"> </span>Bulletin de la Société de
Géographie 18 (2): 241 – 259.</li><li>Castelnau, F. (1843) Essai sur la Floride du Milieu.<span style="mso-spacerun: yes;"> </span>Nouvelles Annales des Voyages et des Sciences
Géographiques 110, 4: 129 – 208.</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> And here are the translations:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Castelnau, F., A.R. Seymour and M.F. Boyd (1948) Essay on
Middle Florida, 1837 – 1838.<span style="mso-spacerun: yes;"> </span>The Florida
Historical Quarterly 26(3): 199 – 255.</li><li>Seymour, A.R. and F. Castelnau (1948) Comte de Castelnau in
Middle Florida, 1837 – 1838.<span style="mso-spacerun: yes;"> </span>Notes
concerning two itineraries from Charleston to Tallahassee.<span style="mso-spacerun: yes;"> </span>The Florida Historical Quarterly 26(4): 300
-324.</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> “Here I was able to form an idea of the character of the
people of this region, by noticing the ramshackle condition of the ordinary
houses, all the windows of which were broken and the doors broken down. I asked the cause of it and I learned that a
few days before all of the inhabitants having got drunk and committed this
havoc.”</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Five of those letters, anyway.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-72006955956923805872022-11-03T12:33:00.002-04:002023-11-23T20:34:36.646-05:00The SNHTHICACBW Marstonia 6: pachyta<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b) The SNHTHICACBW Marstonia IV: pachyta. Pp 253 – 260 in The Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Last time we reviewed the minor hydrobioid taxon <i>Marstonia</i>
from its origin as a subgenus in 1926 through its 1977 promotion by Fred
Thompson, its 1994 death at the hands of Bob Hershler, and its 2002
resurrection by the dynamic duo of Thompson and Hershler working together. And we focused on a subset of <i>Marstonia</i> that
Thompson called, “small narrow hydrobiids that have in common a carinate body
whorl,” abbreviated “SNHTHICACBW.” This
subset includes <i><a href="https://www.fwgna.org/species/hydrobiidae/m_letsoni.html" target="_blank">M. letsoni</a></i> from way up north, which we reviewed in [<a href="https://fwgna.blogspot.com/2016/01/a-new-invasive-gastropod-in-great-lakes.html" target="_blank">19Jan16</a>]
and [<a href="https://fwgna.blogspot.com/2016/02/marstonia-letsoni-quite-literally.html" target="_blank">5Feb16</a>], and which in retrospect, might have been numbered 1 and 2 in this
series. And the subset also includes <i>M.
ozarkensis</i>, which we reviewed in [<a href="https://fwgna.blogspot.com/2020/02/what-was-marstonia-ozarkensis.html" target="_blank">10Feb20</a>] and [<a href="https://fwgna.blogspot.com/2020/03/is-marstonia-ozarkensis-extinct.html" target="_blank">16Mar20</a>], which in retrospect
might have been numbered SNHTHICACBW installments 3 and 4.</p><p>Then after laying all that groundwork, which took almost 700
words, which is approaching my target length for an entire essay, I blathered
on another 1,400 words about the original member of the SNHTHICACBW group,
<i><a href="https://www.fwgna.org/species/hydrobiidae/m_scalariformis.html" target="_blank">Marstonia scalariformis</a></i>. We focused
especially on the ACBW part of the formula, “a carinate body whorl,” dwelling
at length on the variability that carination can demonstrate. And at the eagerly anticipated end of last
month’s essay, we concluded that the ranges of these little hydrobiids can be
vast. The range of <i>M. scalariformis</i>
seems to extend from Illinois to Alabama.
And that they are obscure. You
will not find a population of SNHTHICACBW <i>Marstonia</i> unless you look sharp and
employ special techniques.</p><p>So, when last we left our intrepid malacologist, he was
standing knee-deep in the Flint River at Cherrytree, Alabama, washing stones
into a sawed-off trash can (Site <span style="color: red;"><b>CT</b></span> on the map way down below). He was indeed finding <i>Marstonia
scalariformis</i>. But that was not all.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgfwyDEPb_5qLuMCYhxP5Lzdaur2xunpkNOy-HwKp43Ntf5jLkjJ9doFEEvjAejzjz8azjgRjW7k0YVaRjFUnCuAkzBDY9640ZYzk6LYZqkcuoK2Wv5sUO83qwHOCr2yKwWwx5E3qTjtzG19yzVfwfY9GH2l3wH55szXMi39AwmyJgG-OqYEb_AVUjXoQ/s1000/Flint-River-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="422" data-original-width="1000" height="169" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgfwyDEPb_5qLuMCYhxP5Lzdaur2xunpkNOy-HwKp43Ntf5jLkjJ9doFEEvjAejzjz8azjgRjW7k0YVaRjFUnCuAkzBDY9640ZYzk6LYZqkcuoK2Wv5sUO83qwHOCr2yKwWwx5E3qTjtzG19yzVfwfY9GH2l3wH55szXMi39AwmyJgG-OqYEb_AVUjXoQ/w400-h169/Flint-River-montage.jpg" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">The four hydrobioids of the Flint River</span></td></tr></tbody></table><p>There are four hydrobioids inhabiting the dark recesses of
rocks and organic debris at Cherrytree, as figured above. The <i>Marstonia scalariformis</i> we beat to death
last month. We’ll feature the
lithoglyphid <i><a href="https://www.fwgna.org/species/hydrobiidae/s_parvulus.html" target="_blank">Somatogyrus</a> </i>populations in a pair of essays to be posted later
this winter. Maybe we’ll come back to
<a href="https://www.fwgna.org/species/hydrobiidae/m_arga.html" target="_blank"><i>Marstonia arga</i> </a>at some time further in the future <b><span style="color: #783f04;">[1]</span></b>. What is that fourth hydrobiid? What is <i><a href="https://www.fwgna.org/species/hydrobiidae/m_pachyta_pachyta.html" target="_blank">Marstonia pachyta</a></i>?</p><p>About three paragraphs into the first 700 words of blather I
published last month I mentioned that when Thompson <b><span style="color: #783f04;">[2]</span></b> initially elevated
<i>Marstonia</i> to the genus level in 1977 he described five new species. Among these was a snail “known to occur only
in Limestone Creek and Piney Creek, Limestone County, Alabama” that “is readily
identified by characteristics of both its verge (penis) and shell.” That new species was a not-especially-small, not-particularly-narrow hydrobiid without a notably-carinate body whorl that he
called <i>Marstonia pachyta</i>.</p><p>Thompson figured the <i>M. pachyta</i> penis as demonstrating a
typical spatulate or bladelike form featuring three glandular areas, which I
have labelled using Bob Hershler’s system as a pair of terminal glands (Tg) and
a ventral gland (Vg) in the figure below.
(Thompson also figured another <i>M. pachyta</i> penis missing a second Tg.
Bookmark that for later.) Bob Hershler<b><span style="color: #783f04;"> [3]</span></b> came behind Thompson in 1994 and re-drew the essentially identical figure I have reproduced in
the bottom half of the figure as well.</p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmd8hn2QxKJtiZZshOm66StCvvMfqcKVGeSu0H5cnVj_bk2gIvM8tDrvuCLu1S3f2Y18ficwDArA3rTYQwKNj98QYLN4E3c3bHNpgGfQ0ITXkdnkvOFma-Vq7nmUetNqoMd5xAlc60SNrUHnyFxK4oyX4U-oNx3dMfhn6T9RAOCeRhRBYt5UY7rWi4FQ/s1134/M_pachyta-penis.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1134" data-original-width="645" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmd8hn2QxKJtiZZshOm66StCvvMfqcKVGeSu0H5cnVj_bk2gIvM8tDrvuCLu1S3f2Y18ficwDArA3rTYQwKNj98QYLN4E3c3bHNpgGfQ0ITXkdnkvOFma-Vq7nmUetNqoMd5xAlc60SNrUHnyFxK4oyX4U-oNx3dMfhn6T9RAOCeRhRBYt5UY7rWi4FQ/w114-h200/M_pachyta-penis.jpg" width="114" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>M. pachyta</i> penis <b><span style="color: #783f04;">[4]</span></b></span></td></tr></tbody></table>Regarding the shell morphology of his <i>Marstonia pachyta</i>,
Thompson described the shape as “ovate conical,” and gave the adult length as
ranging 3.3 – 4.0 mm. The little sample figured below came from the type locality in Limestone Creek, east of Mooresville, AL
(marked <b><span style="color: red;">MV</span></b> on the map way down below).<p></p><p>And regarding the range.
Although at the 1977 writing of his description Thompson was only aware
of <i>M. pachyta</i> populations in Limestone and Piney Creeks, on 15Aug2000 he
collected a sample from Bradford Creek at Martin Road <b><span style="color: #783f04;">[5]</span></b> about 7 miles east
(marked <b><span style="color: red;">MR</span></b> below), and on 16Aug2000 he collected a sample from Round Island
Creek at Nuclear Plant Road <b><span style="color: #783f04;">[6]</span></b>, about 10 miles west (marked <b><span style="color: red;">NP</span></b> below).</p><p>From Bradford Creek it is just 18 miles further east to the
Flint River, on the other side of Huntsville.
But here is yet another peculiar lapse in the long, strange career of
Fred Thompson. As far as I can tell,
Thompson only spent one, single day collecting in the entire 500 square mile
Flint River subdrainage, during which time he never recorded a single
hydrobioid. The freshwater gastropod
collection of the FLMNH holds exactly N = 17 lots collected by Fred Thompson
from anywhere in the Flint River or its tributaries, from seven sites he
visited on Saturday, 27Sept69. Among
these lots are 16 of pleurocerids and 1 of <i><a href="https://www.fwgna.org/species/ancylidae/l_fuscus.html" target="_blank">Laevapex fuscus</a></i>. Zero hydrobiids of any species <b><span style="color: #783f04;">[8]</span></b>.</p><p>For comparison, Thompson collected 90 freshwater gastropod
lots (48 hydrobiids) from Limestone Creek over his long career. He then seems to have travelled 25 miles west
to the Flint, crossed it barely wetting a boot toe, travelled another 10 miles
further west, and collected 39 freshwater gastropod lots (8 hydrobiids) from
the Paint Rock River. Does it seem a bit
irresponsible to make statements of the form “known to occur only in Limestone
Creek and Piney Creek” when you haven’t even looked in the (biologically very
similar) Flint River 25 miles away? I
don’t know. I’ve probably done the same
sort of thing myself.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitn6ZFtWERqSRRUR00Fh9Hg75ZGQ5QYghE59PnoyhHdazeX9IhD7AE7iwudQB9tmKFmb2pzaMvq898_zDCffEc0aNIS9JxjqjXHnRR_lng5-4nQ9HWmhDa-280GQ7fusXkLOyeD4rcMjg4ZGgrhn7d7DrpcAWNSMgF3kTwr5wVA2A-wU9cnm651l695A/s640/M_pachyta-group.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="480" data-original-width="640" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitn6ZFtWERqSRRUR00Fh9Hg75ZGQ5QYghE59PnoyhHdazeX9IhD7AE7iwudQB9tmKFmb2pzaMvq898_zDCffEc0aNIS9JxjqjXHnRR_lng5-4nQ9HWmhDa-280GQ7fusXkLOyeD4rcMjg4ZGgrhn7d7DrpcAWNSMgF3kTwr5wVA2A-wU9cnm651l695A/s320/M_pachyta-group.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Marstonia pachyta</i> from Limestone Ck, AL</span></td></tr></tbody></table><p>All of which brings us back, yet a third time, to yours
truly standing knee-deep in the Flint River at Cherrytree, AL (site <b><span style="color: red;">CT</span></b>). As my readership most certainly will have
been able to divine by this point, what I was finding in the bottom of my
sawed-off trash can was important. Yes,
a population of <i>M. pachyta </i>does inhabit the Flint River, matching the shell and
penial morphology of the Limestone Creek type population in all respects. And most of the shells are indeed
“ovate-conical” as described by Thompson in 1977. They are a bit smaller-bodied, however, and
some of them are beginning to show a little bit of carination on the body
whorl. Yes, you heard me right. They are beginning to look like SNHTHICACBW
<i>Marstonia</i>.</p><p>Ten miles east of the Flint, the next south-draining
tributary of the Tennessee River deep enough to wet your mule is the Paint Rock
River. It was from the Paint Rock 0.7 mi
east of Cedar Point (<b><span style="color: red;">CP</span></b>) that Fred Thompson in 2005 described a new SNHTHICACBW
species, <i><a href="https://www.fwgna.org/species/hydrobiidae/m_pachyta_angulobasis.html" target="_blank">Marstonia angulobasis</a></i> <b><span style="color: #783f04;">[9]</span></b>.
Thompson distinguished his <i>M. angulobasis</i> by its shell of “minute size”
(adulthood only 2.5 mm SL), bearing flattened whorls bordered at the periphery
by a distinct angle or cord. He
characterized the penis as bearing “a terminal small apocrine gland.” That’s what Hershler would have called a
“terminal gland” and abbreviated “Tg.”</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSGOFvxnZqnUplBRzg3aZF9zO4vNZiaF8ZL4IEIzKakH7IzA0Ya6xOZEG0-m-8HTsS6NUZJLxPpCq3qCQTgu4YNkxiPN_KFVzMmwBMvVWgP6vveBwNtcsEdZMc1_8K6jHmIQZ5D1JryDrGN1_QknNsb6td76BqNBgy9bOZCcdb4g1PAcAEmU5u_cQXWw/s4670/North-Alabama-for-hydrobiids.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2120" data-original-width="4670" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSGOFvxnZqnUplBRzg3aZF9zO4vNZiaF8ZL4IEIzKakH7IzA0Ya6xOZEG0-m-8HTsS6NUZJLxPpCq3qCQTgu4YNkxiPN_KFVzMmwBMvVWgP6vveBwNtcsEdZMc1_8K6jHmIQZ5D1JryDrGN1_QknNsb6td76BqNBgy9bOZCcdb4g1PAcAEmU5u_cQXWw/w400-h181/North-Alabama-for-hydrobiids.jpg" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Tennessee drainages of North Alabama</span></td></tr></tbody></table><p>So about seven paragraphs above, I asked you to “bookmark”
the tidbit that Fred Thompson also “figured one <i>M. pachyta</i> penis missing a
second Tg.” The dorsal and ventral
aspects of that <i>pachyta</i> penis (his Figs 13C and 13D) are reproduced in the top
half of the figure below, compared to his figure of the penis of <i>M. angulobasis</i>
below. And let me ask you a rhetorical
question. If the <i>M. pachyta</i> penis can
have 2Tg+1Vg, or 1Tg+1Vg, could it also have 1Tg+0Vg <b><span style="color: #783f04;">[10]</span></b>?</p><p>Regarding the shell morphology of the <i>Marstonia</i> population
inhabiting the Paint Rock River, see figures A and B below. Thompson collected his type lot on a canoe
trip, at a spot not readily accessible.
But he also listed “other specimens examined” from Butler Mill, about 2
miles downstream. My observations at
Butler Mill (<b><span style="color: red;">BM</span></b>) suggest a <i>Marstonia</i> population bearing shells quite variable
in their “distinct angle or cord,” or carination, or keel, or whatever anybody
would like to call it. Some of them
(like B below) show one, and some of them (like A below) do not.</p><p>In my September post [<a href="https://fwgna.blogspot.com/2022/09/just-125-species-of-pyrgulopsis-in.html" target="_blank">7Sept22</a>] I went to great lengths to
demonstrate that the distribution of glands on the <i>Marstonia</i> penis shows a
great deal of intrapopulation variability.
And in last month’s post [<a href="https://fwgna.blogspot.com/2022/10/the-snhthicacbw-marstonia-5.html" target="_blank">4Oct22</a>] I went to great lengths to demonstrate
intrapopulation variation in the shell carination. The weight of the evidence before us does not
suggest that Thompson’s <i>M. angulobasis</i> is specifically distinct from his <i>M.
pachyta</i>.</p><p class="MsoNormal"><o:p></o:p></p>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJNR8nWvHILlYnwO2KlO96ppsox2fvsxn7-uPH4ujoE4xn96LDH131WgU50tU4ou4T0RW999GGyrhx-HP4-maNkMWli9S6q16-tHP2DP1SsOIsBjydOU68dR2lhZQtzg1taTXTErw3HDN4Uc54pMhJFJ5RdW0_NUIOi-0IobYkgbqdAa5Tm9y8GwLmPw/s1077/M_angulobasis-penis.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1077" data-original-width="711" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJNR8nWvHILlYnwO2KlO96ppsox2fvsxn7-uPH4ujoE4xn96LDH131WgU50tU4ou4T0RW999GGyrhx-HP4-maNkMWli9S6q16-tHP2DP1SsOIsBjydOU68dR2lhZQtzg1taTXTErw3HDN4Uc54pMhJFJ5RdW0_NUIOi-0IobYkgbqdAa5Tm9y8GwLmPw/w132-h200/M_angulobasis-penis.jpg" width="132" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">pachyta & angulobasis <span style="color: #783f04;"><b>[11]</b></span></span></td></tr></tbody></table><p class="MsoNormal">But let us save Thompson’s nomen “<i>angulobasis</i>” at the
subspecific level, shall we? <b> Let us
henceforth refer to populations of <i>M. pachyta</i> bearing carinate body whorls as
“<i>Marstonia pachyta angulobasis</i> Thompson 2005."</b> And let us remember, as we do, that the FWGNA
Project has adopted the definition of that term as it has been understood since
the birth of the modern synthesis, “populations of the same species in
different geographic locations, with one or more distinguishing traits,” which
means exactly what it says, neither more nor less <b><span style="color: #783f04;">[12]</span></b>.</p><p class="MsoNormal">Now let me go back and pick up those other themes from last
month’s post, that business about SNHTHICACBW <i>Marstonia</i> being widespread and
obscure. Although it will always be
difficult for field biologists to find populations of such obscure little
creatures looking for them, one might not be surprised to find them pop up in
quantitative macrobenthic samples.</p><p class="MsoNormal">Over the last few years, I have been blessed to develop a
professional relationship Ms. Debbie Arnwine, Ms. Patricia Alicea, and Ms.
Carrie Perry of the Tennessee DWR in Nashville who, in the course of their
routine duties, collect and sort huge numbers of quantitative macrobenthic
samples collected from all over the Volunteer State. These they hold for some years, but
ultimately discard.</p><p class="MsoNormal">Sorting through hundreds of old samples released to us by
the TNDEC-DWR, Bob Winters and I have discovered SNHTHICACBW hydrobiids
identifiable as <i>Marstonia pachyta angulobasis</i> in three tributaries of the
Cumberland River, perhaps 100 miles north of the North Alabama focus of the
present essay: Smith Fork of the Caney System (C, below), the West Fork Stones
River south of Nashville (D, below) and in Spring Creek of the Red River system
almost to the Kentucky line (unfigured).
In fact, it seems possible to us that a single, enigmatic SNHTHICACBW
<i>Marstonia</i> shell recovered by our colleague Ryan Evans from the bank of the
Elkhorn Creek north of Frankfort, KY, might represent<i> M. pachyta angulobasis</i>,
rather than <i>M. letsoni</i> as we have tentatively identified it <b><span style="color: #783f04;">[13]</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCTPjNgNMqTt7KuVsqH19Xei0jdqcLiTuDEg7_JVvT8dgCY65mvWJ6ASDn94BlX4RqsfM5q2zlUC2daTcecWiUBCtTKylkDFGb402COM212HDm2dQRAFgh0XuHgPW2JA9XRXladEO3LI0kYr8G6fqCb3OcQU-DnP-NvhhAeW2K2R7RYa6u0RONBOsByA/s1992/M_angulobasis-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="900" data-original-width="1992" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCTPjNgNMqTt7KuVsqH19Xei0jdqcLiTuDEg7_JVvT8dgCY65mvWJ6ASDn94BlX4RqsfM5q2zlUC2daTcecWiUBCtTKylkDFGb402COM212HDm2dQRAFgh0XuHgPW2JA9XRXladEO3LI0kYr8G6fqCb3OcQU-DnP-NvhhAeW2K2R7RYa6u0RONBOsByA/w400-h181/M_angulobasis-montage.jpg" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">A,B = Paint Rock River, C = Smith Fork, D = W.Fk. Stones River</span></td></tr></tbody></table><p class="MsoNormal">So now has come the time to sum up, over all six of the
essays I have contributed on the SNHTHICACBW <i>Marstonia</i>. In 1977 Fred Thompson recognized a group he
called, “small narrow hydrobiids that have in common a carinate body whorl,”
comprising four specific nomina: <i>scalariformis, letsoni, wabashensis</i>, and
<i>ozarkensis</i>. Since that date <i>wabashensis</i>
has been synonymized, while <i>pachyta</i> and <i>angulobasis</i> added.</p><p class="MsoNormal">Populations identified by two of those specific nomina,
<i>scalariformis</i> and <i>pachyta</i>, demonstrate reproductive isolation where the
co-occur in the Flint River at Cherrytree, Alabama. Their shells are distinctive, those of the
former bearing a strong carination extending higher than the body whorl, those
of the latter occasionally bearing weak carination on the body whorl only. Their penial morphology is also distinctive,
that of <i>scalariformis</i> quite slender, that of <i>pachyta</i> bladelike. These are two good biological species.</p><p class="MsoNormal">Evidence presented here suggests that <i>angulobasis</i> is a
subspecies of <i>pachyta</i>. The data on
penial morphology we reviewed back in 2016 suggests that <i>letsoni</i> has affinities
with <i>scalariformis</i>. The evidence we
reviewed in 2020 was too fragmentary to offer any hypothesis whatsoever on
<i>ozarkensis</i>.</p><p class="MsoNormal">And finally. All of
these tiny little snails are widespread and obscure. Their ranges can extend over many, many
states. They are not endemic to
anywhere; they are epidemic everywhere across most of the eastern
interior. Populations come, and
populations go. You cannot find
them. Opening my thesaurus and dumping
it wholesale onto the computer screen flickering before you, the SNHTHICACBW
<i>Marstonia</i> are shadowy, secretive, enigmatic, mysterious, and obscure.</p><p class="MsoNormal"><br /></p><p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Thompson <b><span style="color: #783f04;">[2]</span></b> described <i>Marstonia arga</i> from Guntersville
Reservoir in 1977, but it has since spread up the impounded Tennessee to the
vicinity of Knoxville, and throughout the impounded Cumberland River as
well. It’s an evolutionary winner! Seems unfair to ding the TVA for extincting
some species without crediting them for carp, kudzu, and <i>M. arga</i>, doesn’t it?</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> Thompson, F.G. (1977) The hydrobiid snail genus
<i>Marstonia</i>. Bulletin of the Florida State
Museum 21(3):113-158.</p><p class="MsoNormal"><b><span style="color: #783f04;">[3] </span></b>Hershler, R. (1994)
A review of the North American freshwater snail genus <i>Pyrgulopsis</i>
(Hydrobiidae). Smithsonian Contributions
to Zoology 554: 1 - 115.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Above, <i>Marstonia pachyta</i> penis modified from Thompson
<b><span style="color: #783f04;">[2]</span></b> figure 13A and 13B. Below, <i>Marstonia
pachyta</i> penis from Hershler <b><span style="color: #783f04;">[3]</span></b> figure 53a.
Dorsal on left, ventral on right. Tg = terminal glands, Vg = ventral
gland, P = penial filament.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5] </span></b>FLMNH catalog 279921, collected by FGT on 8/15/2000 from
Bradford Creek at Martin Road, 2 miles south of Madison, AL.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> FLMNH 279628, collected by FGT on 8/16/2000 from Round
Island Creek at County Road 25, 3 miles west of Jones Crossroads, AL. Haggerty & Garner<b><span style="color: #783f04;"> [7]</span></b> were not able to
confirm this record in their exhaustive survey of 2008, however.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Haggerty, T.M. & J.T. Garner (2008) Distribution of the armored snail (<i>Marstonia
pachyta</i>) and slender Campeloma (<i>Campeloma decampi</i>) in Limestone, Piney, and
Round Island Creeks, Alabama.
Southeastern Naturalist 7: 729 – 736.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> And in fact, the entire Flint River (AL) catalog at the
FLMNH is a disappointment. Just N = 50
freshwater gastropod records total from all collectors, the 33 lots not
collected by Thompson undated and obviously ancient.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> Thompson, F.G. (2005)
Two new species of hydrobiid snails of the genus <i>Marstonia</i> from Alabama
and Georgia. The Veliger 47: 175 – 182.</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Yes.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Above, <i>Marstonia pachyta</i> penis modified from Thompson
<b><span style="color: #783f04;">[2]</span></b> figure 13C and 13D. Below, <i>Marstonia
angulobasis</i> penis from Thompson <b><span style="color: #783f04;">[9]</span></b> figure 18a and 18b. Dorsal on left, ventral
on right. Tg = terminal gland, Vg = ventral gland, P = penial filament.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> For more on the subspecies concept as applied by the
FWGNA Project, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>What is a subspecies [<a href="https://fwgna.blogspot.com/2014/02/what-is-subspecies.html" target="_blank">4Feb14</a>]</li><li>What subspecies are not [<a href="https://fwgna.blogspot.com/2014/03/what-subspecies-are-not.html" target="_blank">5Mar14</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> For more about that single, enigmatic SNHTHICACBW shell
from Kentucky, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Is Marstonia ozarkensis extinct? [<a href="https://fwgna.blogspot.com/2020/03/is-marstonia-ozarkensis-extinct.html" target="_blank">16Mar20</a>]</li></ul><p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-60168706690269380472022-10-04T15:39:00.006-04:002023-11-23T20:30:33.601-05:00The SNHTHICACBW Marstonia 5: scalariformis<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b) The SNHTHICACBW Marstonia III: scalariformis. Pp 243 – 252 in The Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Our modern understanding of the North American hydrobiid
genus <i>Marstonia</i> is entirely to the credit of two men, as similar as they were
different, Dr. Fred Thompson and Dr. Bob Hershler. I featured the former colleague, who passed
away five years ago, in a pair of essays posted on this blog in 2017 [<a href="https://fwgna.blogspot.com/2017/02/fred-thompson-steve-chambers-and.html" target="_blank">15Feb17</a>]
[<a href="https://fwgna.blogspot.com/2017/03/fred-thompson-elizabeth-mihalcik-and.html" target="_blank">14Mar17</a>]. I profiled the latter
colleague, now retired, in an essay I published in July [<a href="https://fwgna.blogspot.com/2022/07/my-buddy-bob.html" target="_blank">5July22</a>]. And to appreciate their contributions to our
understanding of the most enigmatic group of gastropods inhabiting the fresh
waters of the American East, let’s back up and get a running start at it.</p><p>F. C. Baker <b><span style="color: #783f04;">[1]</span></b> described the subgenus <i>Marstonia</i> in 1926 to
distinguish Henry Pilsbry’s familiar and widespread <a href="https://www.fwgna.org/species/hydrobiidae/m_lustrica.html" target="_blank"><i>Amnicola lustrica</i> </a><span style="color: #783f04; font-weight: bold;">[2]</span><span> from Thomas Say's equally familiar and widespread <a href="https://www.fwgna.org/species/hydrobiidae/a_limosa.html" target="_blank"><i>Amnicola limosa</i></a>. </span>Baker made
this distinction on the basis of shell and radula, taking no notice of penial
morphology at the time. He recognized
seven species in his new subgenus <i>Marstonia</i> inhabiting the lakes of Wisconsin,
all of which would either be synonymized under <i>lustrica</i>, or subsequently split
out to <i>Lyogyrus</i>, leaving his subgenus <i>Marstonia</i> effectively monotypic.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdVXEukt9pFc57aEC8nHkEGfMtfmXv3oBN_7EpCCB-mG3GnVXB6nbFeCIr_eFRZDSy-XQS9v9m4P-yc1JzVkeQGFDVWd9MSlwwDZthi8DO_B41LYdVP0JGlmkydLeL7Lr1T_APEf-erOtOPRmm6InELhwRV1XAjVFgMh6yilBrBjyfQxoqRKVeH_e5nQ/s2124/M_scalariformis-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1200" data-original-width="2124" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdVXEukt9pFc57aEC8nHkEGfMtfmXv3oBN_7EpCCB-mG3GnVXB6nbFeCIr_eFRZDSy-XQS9v9m4P-yc1JzVkeQGFDVWd9MSlwwDZthi8DO_B41LYdVP0JGlmkydLeL7Lr1T_APEf-erOtOPRmm6InELhwRV1XAjVFgMh6yilBrBjyfQxoqRKVeH_e5nQ/s320/M_scalariformis-montage.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>M. scalariformis</i>, Cherrytree, AL</span></td></tr></tbody></table><p>It was Fred Thompson who, in his seminal 1977 monograph <b><span style="color: #783f04;">[3]</span></b>,
raised <i>Marstonia</i> to the genus level, highlighting a distinction that Berry <b><span style="color: #783f04;">[4]</span></b>
had made in the penial morphologies of <i>limosa</i> and <i>lustrica</i>. Thompson included three previously described
species in <i>Marstonia</i>: Pilsbry’s (1890) <i>lustrica</i>, Pilsbry’s (1895) <i><a href="https://www.fwgna.org/species/hydrobiidae/m_ogmor.html" target="_blank">olivacea</a></i> <b><span style="color: #783f04;">[5]</span></b>
and his own (1969) <i><a href="https://www.fwgna.org/species/hydrobiidae/m_agarhecta.html" target="_blank">agarhecta</a></i>. To this
short list he added five new species: <i><a href="https://www.fwgna.org/species/hydrobiidae/m_arga.html" target="_blank">arga</a>, castor, <a href="https://www.fwgna.org/species/hydrobiidae/m_halcyon.html" target="_blank">halcyon</a>, <a href="https://www.fwgna.org/species/hydrobiidae/m_pachyta_pachyta.html" target="_blank">pachyta</a></i>, and
<i><a href="https://www.fwgna.org/species/hydrobiidae/m_ogmor.html" target="_blank">ogmorhaphe</a></i> <b><span style="color: #783f04;">[6]</span></b>. This eight-species model
of <i>Marstonia</i> was the understanding brought down from the mountain by Jack Burch
in 1982 <b><span style="color: #783f04;">[7]</span></b>.</p><p>In his 1977 closing remarks on “species of questionable
status,” however, Thompson suggested that four species “currently placed in
<i>Pyrgulopsis</i> <b><span style="color: #783f04;">[8]</span></b>” might “actually belong in <i>Marstonia</i>.” Here he listed <a href="https://www.fwgna.org/species/hydrobiidae/m_scalariformis.html" target="_blank"><i>scalariformis</i> </a>(Wolf 1869),
<i><a href="https://www.fwgna.org/species/hydrobiidae/m_letsoni.html" target="_blank">letsoni</a></i> (Walker 1901), <i>wabashensis </i>(Hinkley 1908) and <i>ozarkensis</i> (Hinkley
1915), noting “these are <b>Small Narrow Hydrobiids That Have In Common A Carinate
Body Whorl</b>.” Let us henceforth refer to
this subgroup as the “SNHTHICACBW” <i>Marstonia</i>.</p><p>The broad-brush similarity in penial morphology between his
eight newly minted <i>Marstonia</i> species and those four SNHTHICACBW species, which
since 1886 had been allocated to <i>Pyrgulopsis</i>, seems to have worked on
Thompson’s mind, however. And I
speculate that a rising young star in the constellation of hydrobioid
systematics also had something to do with it, as well. Because in 1987 the dynamic duo of Bob
Hershler and Fred Thompson united to synonymize Baker’s <i>Marstonia</i> under Call
& Pilsbry’s <i>Pyrgulopsis</i> <b><span style="color: #783f04;">[9]</span></b>.</p><p>The next advance in the inexorable march of tiny-snail
science came in 1994, with Bob Hershler’s masterful “Review of the North
American Freshwater Snail Genus <i>Pyrgulopsis</i>” <b><span style="color: #783f04;">[10]</span></b>. As we mentioned back in July, my buddy Bob
counted 54 “Western American Species” and 11 “Eastern American Species” in that
work, including Fred Thompson’s original eight plus three of Thompson’s
SNHTHICACBW: <i>letsoni, ozarkensis</i> and <i>scalariformis</i>.</p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiP3G5IMbtVL9-mplBX42pw9S9yw73QalmIiL-GXW6bfL3yMVwW2STv8PeRwt9-RjUHv3qbktnPQ1mWF2zgg0Pjav9rNYp5f34syZglY54nTIEwK6YQa7mbTA0wWvIRobG3E_59EXTFsDbqtVEt1h-s9alP2LcePnzQB5vtQSOnsSC3wzcEfY9ytMevrA/s864/scalariformis&letsoni-penial.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="828" data-original-width="864" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiP3G5IMbtVL9-mplBX42pw9S9yw73QalmIiL-GXW6bfL3yMVwW2STv8PeRwt9-RjUHv3qbktnPQ1mWF2zgg0Pjav9rNYp5f34syZglY54nTIEwK6YQa7mbTA0wWvIRobG3E_59EXTFsDbqtVEt1h-s9alP2LcePnzQB5vtQSOnsSC3wzcEfY9ytMevrA/w200-h192/scalariformis&letsoni-penial.jpg" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Marstonia</i> penis morphology <b><span style="color: #783f04;">[10]</span></b></span></td></tr></tbody></table>And a mere eight years later, as if to validate their
dynamic credentials before the Judgement Seat of Malacology Eternal, the duo of
Thompson and Hershler <b><span style="color: #783f04;">[11] </span></b>resurrected <i>Marstonia</i> back to full genus level on
the basis of female reproductive anatomy <b><span style="color: #783f04;">[12],</span></b> reallocating Hershler’s list of
11 eastern species into it once again, plus <i>comalensis</i> of Pilsbry & Ferriss
1906.<p></p><p>The systematic status of the SNHTHICACBW hydrobioids was the
dasher in 76 years of taxonomic churn.
We have previously featured two elements of this enigmatic group in a
pair of essays each, reviewing the mighty efforts of previous workers to
understand the tangled evolutionary relationships among them. In [<a href="https://fwgna.blogspot.com/2016/01/a-new-invasive-gastropod-in-great-lakes.html" target="_blank">19Jan16</a>] and [<a href="https://fwgna.blogspot.com/2016/02/marstonia-letsoni-quite-literally.html">5Feb16</a>] we reviewed the
situation with <i>Marstonia letsoni</i>, and in [<a href="https://fwgna.blogspot.com/2020/02/what-was-marstonia-ozarkensis.html" target="_blank">10Feb20</a>] and [<a href="https://fwgna.blogspot.com/2020/03/is-marstonia-ozarkensis-extinct.html" target="_blank">16Mar20</a>] we covered
<i>Marstonia ozarkensis</i>. For the remainder
of this essay, which has actually turned out to be the fifth installment of a
series I did not know I was starting back in 2016, we will focus on the
original member of the group, <i>M. scalariformis</i>, together with its synonyms and
forms.</p><p><i>Pyrgula scalariformis</i> was described by Wolf (1869) from a
single empty shell collected along the Illinois River in Tazewell County,
Illinois <b><span style="color: #783f04;">[13]</span></b>. And the original
rationale that Call & Pilsbry offered for their description of the new
genus, <i>Pyrgulopsis</i>, back in 1886 was to contain <i>scalariformis</i> and their own
virtually-identical species from the Illinois bank of the Mississippi river at
Rock Island, <i>P. mississippiensis</i> <b><span style="color: #783f04;">[8]</span></b>.
Hershler <b><span style="color: #783f04;">[10]</span></b> considered both <i>mississippiensis</i> and <i>wabashensis</i> (Hinkley
1908) synonyms of <i>scalariformis</i>, the latter described from the Wabash River in
Indiana, perhaps 200 miles southeast.
All three nominal species have been considered extinct from their type
localities by multiple authorities.
Hershler made his anatomical observations from a population collected in
the Meramec River of Missouri, perhaps 200 miles south of Wolf’s type locality.</p><p>Hershler’s <b><span style="color: #783f04;">[10</span></b>] figure 53b showed an overall penial
morphology really quite different from the peculiar blade-shaped structure
mounted by the western <i>Pyrgulopsis</i> we beat to death last month, or indeed
typical eastern <i>Marstonia</i> such as <i>M. lustrica</i>, which we figured back on
[<a href="https://fwgna.blogspot.com/2016/02/marstonia-letsoni-quite-literally.html" target="_blank">5Feb16</a>]. The<i> M. scalariformis</i> penis
actually looks like a penis, with a prominent hose-shaped pointy-thing and a
single reduced gland sticking out the side, which Hershler simply called a
“terminal gland.” It is very reminiscent
of the penis of the SNHTHICACBW <i>Marstonia letsoni</i> that E. G. Berry<b><span style="color: #783f04;"> [4] </span></b>figured
from up in Michigan, which we also reprinted in our essay of [<a href="https://fwgna.blogspot.com/2016/02/marstonia-letsoni-quite-literally.html" target="_blank">5Feb16</a>]. I’ve pasted Hershler’s figure 52e of the
<i>letsoni</i> penis next to his 53b of the <i>scalariformis</i> above, to refresh your
memory. The only difference seems to be
a larger terminal gland in <i>letsoni</i>.</p><p>Turning now to the shell morphology. Some significant fraction of Hershler’s
Missouri sample did indeed bear shells every bit as “scalariform” as Wolf’s
type specimen from Illinois. This is the
ACBW predicate of Thompson’s SNHTHICACBW, which Hershler called a “peripheral
keel.” But that carination or keel
varied “from weak to well-developed.”
And strangely, although Hinkley’s <b><span style="color: #783f04;">[14]</span></b> description of <i>P. wabashensis</i> emphasized
the absence of a carination/keel, Hershler’s reexamination of Hinkley’s Indiana
type material also revealed that “many of the paratypes from the type locality
(the Wabash) are carinate and very closely resemble some <i>scalariformis</i>.”</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEij1wBv2YNmD1QpA369pmmRkwwsxPgGd8cpJmFBJuPIXw4LijgvAQkG-B_CLoMEYkvPT_J_fBzDaYr9TCGVYdIyRE5yad_4gCFg5lSrGcvGqW6pL90yhFnIwXMFzZ8W-fgoA7OafW7U6ubuPUAqo2FuMR_E3k06Pm6MNbNHKATvztiKUsz5magSAbadfw/s1656/Shimek-scalariformis.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="615" data-original-width="1656" height="119" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEij1wBv2YNmD1QpA369pmmRkwwsxPgGd8cpJmFBJuPIXw4LijgvAQkG-B_CLoMEYkvPT_J_fBzDaYr9TCGVYdIyRE5yad_4gCFg5lSrGcvGqW6pL90yhFnIwXMFzZ8W-fgoA7OafW7U6ubuPUAqo2FuMR_E3k06Pm6MNbNHKATvztiKUsz5magSAbadfw/s320/Shimek-scalariformis.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Shimek's <i>P. mississippiensis </i><b><span style="color: #783f04;">[15]</span></b></span></td></tr></tbody></table><p>The situation with the other <i>scalariformis</i> synonym, Call
& Pilsbry’s <i>mississippiensis</i>, is identical.
In 1892 the University of Iowa Professor Bohumil Shimek <b><span style="color: #783f04;">[15]</span></b> published
an excellent paper in an obscure journal <b><span style="color: #783f04;">[16]</span></b> exhaustively cataloguing shell
variation in “more than 1500” subfossil SNHTHICACBW collected from Pilsbry’s
type locality on the bank of the Mississippi River. Quoting Shimek verbatim:</p><p></p><blockquote><span style="font-size: x-small;">“The series is an unbroken one, the species varying from the
ecarinate forms which are scarcely angled at the periphery of the body-whorl,
and in which the suture is not impressed, to forms in which the carina is
elevated and extends quite to the apex, and in which the suture is deeply
impressed.”</span></blockquote><p></p><p>Importantly, three different early-twentieth century authors
reported SNHTHICACBW species identified as either <i>mississippiensis</i> or
<i>scalariformis</i> from Shoal Creek, a tributary of the Tennessee River in North
Alabama. The initial collection,
identified as <i>Pyrgula mississippiensis</i>, was made by Hinkley and confirmed by
Bryant Walker <b><span style="color: #783f04;">[17]</span></b>. F. C. Baker <b><span style="color: #783f04;">[18]
</span></b>dissected a fresh sample he identified as <i>Pygrulopsis scalariformis</i> from Shoal
Creek, figuring shell, operculum, and radula, agreeing with Shimek that
<i>mississippiensis</i> should be synonymized underneath it. Baker did not offer us any anatomical data on
his Shoal Creek sample, alas.</p><p>The special importance of this record, which I cannot find
any reason to doubt, is that it extends the range of <i>scalariformis</i> 500 km south
from Indiana into drainages of the Southern Interior. But alack, the same fate seems to have
befallen the Shoal Creek population as has been suffered by Wolf’s original
<i>scalariformis</i>, Pilsbry’s <i>mississippiensis</i>, and Hinkley’s <i>wabashensis</i>. Repeated efforts by Thompson and Hershler
failed to rediscover any living specimens.
Shoal Creek is today inhabited by a similar species better adapted to
trashy, lentic environments, <i>Marstonia arga</i>.</p><p>All of which brings us to the present day, and the first
person. Many have been the sleepless
nights I have passed in recent years, combing through the yellowed pages of dusty
journals, preparing for the expansion of the FWGNA Project through the
Tennessee drainages of North Alabama <b><span style="color: #783f04;">[19]</span></b>.
And many have been the Latin binomina assigned to the hydrobioid fauna
of those rich waters. And many have been
the hours I have waded in the shallows of Shoal Creek, wiping rocks in a
sawed-off trashcan, hunting for <i>M. scalariformis</i> in the drainage of The
Tennessee. To no avail.</p><p>The SNHTHICACBW <i>Marstonia</i> are really, really hard to
find. At an AMU meeting many years ago I
asked Fred Thompson how he did it. And
seven of the twelve words he ever spoke to me were these: “I wash rocks in a
white bucket.”</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-Gd7CS2ySi3hvnSo2bKcR0yIVHB_yIEI8uNiPt5cFf0OS3UXkU3DkF3IqhgagzwU7O9vWEdPp7ZU7L88jW6NzdhZYPYJW37wqWTPVB8v0XEOnhnjTP9Gf01JC2ewv4aVMnO_yK3dcNjoDTYDMYIpVydo7IF0Cciw0VUiOc0EThYShSp8hE0j7IZ50hw/s640/Wash-bucket-sm.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="480" data-original-width="640" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-Gd7CS2ySi3hvnSo2bKcR0yIVHB_yIEI8uNiPt5cFf0OS3UXkU3DkF3IqhgagzwU7O9vWEdPp7ZU7L88jW6NzdhZYPYJW37wqWTPVB8v0XEOnhnjTP9Gf01JC2ewv4aVMnO_yK3dcNjoDTYDMYIpVydo7IF0Cciw0VUiOc0EThYShSp8hE0j7IZ50hw/w320-h240/Wash-bucket-sm.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Washing vegetation into a white bucket</span></td></tr></tbody></table><p>I have personally found the walls of standard
pickle-dimension buckets too deep to effectively inspect and recover little 3
mm items from the bottom of. So, a few
years ago I bought a white kitchen trashcan from the Walmart and sawed it off
at about six inches deep, yielding a vessel that is more like a very-deep
tray. And I pull rocks up from the
rapids – especially rocks covered with <i>Podostemum</i> or bryophytes – and wipe them
off into the vessel. I also target
larger items of organic debris – sticks and so forth, and the stems of emergent
vegetation. And then I slosh the bottom
mess around and slide it off like I was panning for gold, which in the
malacological world, I suppose I am.</p><p>I have found this technique effective for surveying the
diverse hydrobioid fauna of North Alabama, about which we will have much more
to say in coming months. But as for
<i>Marstonia scalariformis</i> in Shoal Creek – goose egg, bagel, O-fer.</p><p>Ah, but! Not all of
the reference materials to which I have turned these sleepless nights have been
yellowed tomes. Reference to the Global
Biodiversity Information Facility <b><span style="color: #783f04;">[20] </span></b>returns 62 records of <i>Marstonia</i> (or
<i>Pyrgulopsis</i>) <i>scalariformis</i> (or <i>mississippiensis</i>) held in national collections,
16 of which are from North Alabama.
Almost all of those 16 records are old, historic lots from Shoal
Creek. But late one night I was pleased
to find in a GBIF data download <b><span style="color: #783f04;">[21] </span></b>three recent records of <i>Marstonia
scalariformis</i> (1 USNM, 2 NCSM) collected by Jeff Garner, working in the Flint
River just east of Huntsville, about 70 miles east of Shoal Creek.</p><p>And with that intelligence on a clipboard riding on the
passenger seat of my little Mazda pickup, in 2021 I was indeed able to confirm
a population of <i>Marstonia scalariformis</i> deep in the bryophytes and periphyton
covering the rocks in rapids of the Flint River at Cherrytree, AL. Witness the figure that opened this essay,
way up above.</p><p>To summarize. The
essay you have just suffered through, discursive as it most certainly has been,
has nevertheless managed to touch three points.
First, the ranges of SNHTHICACBW <i>Marstonia</i> can be vast. The straight-line distance from the bank of
the Mississippi River at Rock Island, Illinois, to the shoals of the Flint
River at Cherrytree, Alabama is 900 km.
Second, populations of <i>M. scalariformis</i> can vary strikingly in their
shell morphology, especially with regard to carination. And third, those doggone things are tough to
find. Populations come, and populations
go. It is hard to imagine how an
itinerant malacologist, such as yours truly, might find a <i>Marstonia
scalariformis</i> population anywhere, ever, unless he is consciously looking for
one. Special techniques are
required.</p><p>Or alternatively, I suppose, biologists who are NOT looking for them might turn them up in quantitative macrobenthic samples, perhaps? In any case.
<b>The SNHTHICACBW <i>Marstonia</i> are, in three words, widespread, polymorphic,
and obscure.</b> Carry those three words
forward, and we’ll see you all next month.</p><p><br /></p><p><u>Notes</u></p><p><b><span style="color: #783f04;">[1]</span></b> Baker, F. C. (1926) Nomenclatural notes on American
fresh water Mollusca. Transactions of the Wisconsin Academy of Sciences, Arts,
and Letters 22:193-205.</p><p><b><span style="color: #783f04;">[2] </span></b>Of course, a
freshwater gastropod as common and widespread as what we identify today as
<i>Marstonia lustrica</i> was well known before Pilsbry described it (or re-described
it) in 1890. The taxonomic situation was
complicated by uncertainty over the identity of Thomas Say’s (1821) <i>Paludina
lustrica</i>. See:</p><p></p><ul style="text-align: left;"><li>Baker, H. B. (1960)
<i>Lustrica (Paludina</i>) Say, 1821 (Gastropoda): Proposed suppression under
the plenary powers. Z.N.(S.) 730. Bulletin of Zoological Nomenclature 18: 146 –
148.</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[3] </span></b>Thompson, F.G. 1977. The hydrobiid snail genus
<i>Marstonia</i>. Bulletin of the Florida State
Museum 21(3):113-158. </p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Berry, E. G. (1943) The Amnicolidae of Michigan:
distribution, taxonomy and ecology.
Miscellaneous Publications of the Museum of Zoology, University of
Michigan 57: 1 – 68.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Thompson
considered Pilsbry’s <i>M. olivacea</i> “of uncertain status and probably
extinct.” We will have much more to say
about this in a future post.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Thompson spelled the specific nomen with two pees,
“<i>ogmorphaphe</i>” at the heading of his 1977 description, but just the single pee
“<i>ogmorhaphe</i>” enough times subsequently to make the one-pee spelling stick.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> This is a difficult work to cite. J.B. Burch’s <i>North
American Freshwater Snails</i> was published in three different ways. It was initially commissioned as an
identification manual by the US EPA and published by the agency in 1982. It was also serially published in the journal
Walkerana (1980, 1982, 1988) and finally as a stand-alone volume in 1989
(Malacological Publications, Hamburg, MI).</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Call R. E. & Pilsbry H. A. (1886). On
<i>Pyrgulopsis</i>, a new genus of rissoid mollusk, with description of two new
forms. Proceedings Davenport Academy of Natural Sciences 5: 9-14.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> Hershler, R., and F.G. Thompson (1987) North American Hydrobiidae (Gastropoda:
Rissoacea): redescription and systematic relationships of <i>Tryonia</i> Stimpson,
1865 and <i>Pyrgulopsis</i> Call and Pilsbry, 1886. The Nautilus 101:25-32.</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Hershler, R. (1994)
A review of the North American freshwater snail genus <i>Pyrgulopsis</i>
(Hydrobiidae). Smithsonian Contributions
to Zoology 554: 1 - 115.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Thompson, F. G. & R. Hershler (2002) Two genera of North American freshwater
snails: <i>Marstonia</i> Baker, 1926, resurrected to generic status, and <i>Floridobia</i>,
new genus (Prosobranchia: Hydrobiidae: Nymphophilinae). The Veliger 45: 269 - 271.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> The occurrence of a large extension of the albumen
gland into the pallial roof is a unique <i>Marstonia</i> characteristic <b><span style="color: #783f04;">[10]</span></b>. Molecular phylogenetic analyses have also
supported the distinction between <i>Marstonia</i> and <i>Pyrgulopsis</i>, and the retention
of both genera in the Hydrobiidae sensu strictu. See:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Hershler,R., Liu,H.-P. and Thompson,F.G. (2003) Phylogenetic
relationships of North American nymphophiline gastropods based on mitochondrial
DNA sequences. Zool. Scr. 32 (4): 357-366.</li><li>Liu, H., and R. Hershler (2005)<span style="mso-spacerun: yes;"> </span>Molecular systematics and radiation of
western North American nympholine gastropods. Molecular Phylogenetics and
Evolution 34: 284-298.</li><li>Wilke T., Haase M., Hershler R., Liu H-P., Misof B., Ponder
W. (2013)<span style="mso-spacerun: yes;"> </span>Pushing short DNA fragments to
the limit: Phylogenetic relationships of “hydrobioid” gastropods (Caenogastropoda:
Rissooidea).<span style="mso-spacerun: yes;"> </span>Molec. Phyl. Evol. 66: 715
– 736.</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> Wolf, J. (1869)
Descriptions of three new species of shells. American Journal of Conchology 5: 198.</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Hinkley, A. A. 1908. A new species of <i>Pyrgulopsis</i>.
Nautilus 21: 117-118.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> Bohumil Shimek (1861 – 1937) should be better known in
the malacological community today than he is.
Variously listed as a botanist, a zoologist, a geologist, a
conservationist, and an engineer, he published widely in a variety of
disciplines, including quite a few papers in The Nautilus 1888 – 1936. There’s a photo of him on his Wikipedia page,
if you are curious.</p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> I cannot help but think that, if Shimek’s conclusion
had supported the validity of Pilsbry’s <i>P. mississippiensis</i>, this paper would
have been published in The Nautilus:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Shimek, B. (1892) <i>Pyrgulopsis scalariformis</i> (Wolf) Call and
Pilsbry. Bulletin from the Laboratories
of Natural History of the State University of Iowa 2: 168 – 174.</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> Hinkley, AA (1906) Some shells of Mississippi and
Alabama. Nautilus, 20:40-44. Walker B
(1906) New and little known species of Amnicolidae. Nautilus, 19:114-117.</p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> Baker, F.C. (1928) Freshwater Mollusca of Wisconsin,
Part I, Gastropoda. Bull. Wisc. Geol. Natur. Hist. Survey, no. 70. Madison: University of Wisconsin Press. Baker simply wrote (pg 138) , “Animal: Not
examined or described as far as known.”
Why my hero F. C. Baker didn’t seize the opportunity to describe the
penial morphology of the fresh sample of <i>M. scalariformis</i> before him, I cannot
say. I admit that I am a bit
disappointed. With page 138, anyway.</p><p class="MsoNormal"><b><span style="color: #783f04;">[19] </span></b>Grand opening announced this spring:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Freshwater Gastropods of the Tennessee/Cumberland [<a href="https://fwgna.blogspot.com/2022/05/freshwater-gastropods-of.html" target="_blank">16May22</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[20]</span></b> I could just as easily have referred to the IDigBio
database and obtained the same results, I feel sure. I don’t know why I chose GBIF over
IDigBio. See:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>20 Years of Progress in the Museums [<a href="https://fwgna.blogspot.com/2019/05/20-years-of-progress-in-museums.html" target="_blank">22May19</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[21]</span></b> Here is my direct download from GBIF, accessed
10Feb22. Extract and open the text file
called “occurrence” in excel, tab delimited: <a href="https://doi.org/10.15468/dl.mqfb8b">https://doi.org/10.15468/dl.mqfb8b</a></p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-12646648944785533852022-09-07T09:02:00.002-04:002023-11-23T20:13:35.815-05:00Just 125 species of Pyrgulopsis in the American West<p><span style="font-size: xx-small;">Editor’s Notes - If you
are looking for something citable, the gray-literature report upon which the
following essay is based can be downloaded as FWGNA Circular #6 from footnote
<b><span style="color: #783f04;">[1]</span></b> below. This essay was subsequently published as: Dillon, R.T., Jr.
(2023b) Just 125 species of Pyrgulopsis in the American West. Pp 233 – 242 <b>in</b> The Freshwater
Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other
Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p class="MsoNormal"><o:p></o:p></p><p>In July [<a href="https://fwgna.blogspot.com/2022/07/my-buddy-bob.html" target="_blank">6July22</a>] we reviewed the career of the
USNM-Smithsonian’s Dr. Robert Hershler, for over 30 years the undisputed
authority on the hydrobioid freshwater gastropods of North America. Running our finger through the checklist that
my buddy Bob published with Hsiu-Ping Liu in 2017 <span style="color: #783f04;"><b>[2]</b></span>, we counted “126 species
of <i>Pyrgulopsis</i> inhabiting the waters of the Western United States, 107 of which
Bob Hershler was the author.”</p><p>Journey back with me now to a bleak Tuesday morning in May
of 2020. The ivory towers of Academia
were locked and bolted, the store shelves stripped bare of toilet paper <b><span style="color: #783f04;">[3]</span></b>,
the streets silent save for the rattle of wooden handcarts, and rhythmic
appeals to bring out the dead. And I opened
my email inbox and found a message from Hsiu-Ping. She asked me if I would be “interested in
working on a project to determine the species status of <i>Pyrgulopsis vinyardi</i>
and <i>P. gibba</i>.” And here was my reply:</p><p></p><blockquote><span style="font-size: x-small;">“Well, OK, maybe. It
would take me a while to get up to speed on the Western hydrobioids, and the
maximum speed I could ever achieve would look like standing still, next to Bob
Hershler. But Bob’s not taking any more
laps around the track, and I am.”</span></blockquote><p></p><p>Thus encouraged, sort-of, Hsiu-Ping proceeded to lay out the
situation. Bob had described <i>Pyrgulopsis
gibba</i> from the northwestern Great Basin Desert of California, Nevada, and
Oregon in a relatively small paper published in 1995 <b><span style="color: #783f04;">[4]</span></b> and followed with a
description of <i>P. vinyard</i>i endemic to "two springs in the Squaw Valley drainage" of north-central Nevada in his big monograph of
1998 <b><span style="color: #783f04;">[5]</span></b>. The two bore shells strikingly
different in the relative size of their body whorls, and penises notably
different in their morphologies as well.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi1GRUluiX24METlKXg9TOT9vQNu9YFlCg9kPTjIq737vgZZ5Eq8tOCvdzQU9rj3oX8-Ma_rENAZ2T-JxqR5KsheHS8rsRmTc9yBYcfG5X60E9bb_-sO5bTyN1w7Tw1flMv2N647PY87vyF80CpT-u3-NxHTgEZiwUISCN0SE_Lb22Q_k1NLGGwWOGSLQ/s530/vinyardi&gibba.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="369" data-original-width="530" height="223" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi1GRUluiX24METlKXg9TOT9vQNu9YFlCg9kPTjIq737vgZZ5Eq8tOCvdzQU9rj3oX8-Ma_rENAZ2T-JxqR5KsheHS8rsRmTc9yBYcfG5X60E9bb_-sO5bTyN1w7Tw1flMv2N647PY87vyF80CpT-u3-NxHTgEZiwUISCN0SE_Lb22Q_k1NLGGwWOGSLQ/s320/vinyardi&gibba.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Pyrgulopsis vinyardi</i> <b><span style="color: #783f04;">[5]</span></b> and <i>P. gibba</i> <b><span style="color: #783f04;">[4]</span></b></span></td></tr></tbody></table><p>Regarding penial morphology, see the figure below. I have marked the part of the penis that
actually does the job, really just a simple filament, with the red letter
“P.” Everything else in Bob’s
dorsal-and-ventral figures labelled <i>P. vinyardi</i> (boxed), and in his three
dorsal-and-ventral figures labelled <i>P. gibba</i>, is the ridiculously enlarged and
elaborate penial lobe characteristic of <i>Pyrgulopsis</i>. If you’re curious to see a
whole mount of the actual organ itself, look back at my July post [<a href="https://fwgna.blogspot.com/2022/07/my-buddy-bob.html" target="_blank">6July22</a>].</p><p>The distribution of glandular regions on the surface of this
spatulate or blade-shaped lobe has for many years been considered diagnostic of
hydrobiid species. Bob has marked dorsal
glands as “Dg,” ventral glands as “Vg” and terminal glands as “Tg.”</p><p>Bob wrote in his description of <i>P. gibba</i>: “This species is
unique among members of the genus (as of 1995) in having penial ornament of
terminal gland, Dg3, and ventral gland.”
He went on to observe, however, “Dg3 often present, either as a small
papule (sometimes double) or large raised unit.” Note the modifier, “often.” Bob figured one <i>P. gibba</i> penis that had no
Dg3 at all. See the Dg3 regions
encircled in red. And in 1998 he noted
that the development of the ventral gland often varies as well.</p><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8fbQWWR-WFhEhnrvXmhl7i9nBqdG27ww15jOOwK0Iu06cAk4aL-ZQVFbR9iR_yC8GgJQPa16HsAHS3SNmB6-dU3FWoo37Rshtkxx2E6sQAE8R0sfKxmuYUd8q1O2Rg28qRYJhGs18c4dKespBUpwT0M9E31wdhwqe8Va1l3lLHa0iwtnFZ5tzkZNu_g/s953/gibba&vinyardi-penial.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="953" data-original-width="891" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8fbQWWR-WFhEhnrvXmhl7i9nBqdG27ww15jOOwK0Iu06cAk4aL-ZQVFbR9iR_yC8GgJQPa16HsAHS3SNmB6-dU3FWoo37Rshtkxx2E6sQAE8R0sfKxmuYUd8q1O2Rg28qRYJhGs18c4dKespBUpwT0M9E31wdhwqe8Va1l3lLHa0iwtnFZ5tzkZNu_g/s320/gibba&vinyardi-penial.jpg" width="299" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Penial morphology, modified from Hershler <b><span style="color: #783f04;">[6]</span></b></span></td></tr></tbody></table>In his description of <i>P. vinyardi</i> three years later, Bob
wrote, “Penial ornament a small terminal gland, large Dg1, small Dg2, small
Dg3, additional dorsal gland on lobe, and large ventral gland.” So, upon dissection, <i>P. vinyardi</i> males are
expected to demonstrate the entire smorgasbord of glands, including everything
seen on <i>P. gibba</i> plus Dg1 and (usually) Dg2.
He noted later, however, that Dg2 was “rarely absent.”<p></p><p>The obvious analogy is to “lock-and-key” reproductive
isolation such as has been widely documented across the Phylum Arthropoda,
except that the gastropod lock is a bag, and the gastropod key is a sock.</p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6x4vSZ3-rBhheIwbOSyLQX31jRNf49rQzVCFwrJUgmJy1xaDFyHkslU_8Y2IrHmpFY0BV9LtzM-cQu7t-98a7AmwJqkaKX32AVaQfI46r-3NRyrHWbywHvmHHR3m1ujmPEGybRtXpgJ_ZSObPy0z9grhNYD5ubVtMHjZPia7DG0uwBRGGQN8Yw7P9eQ/s261/Im-not-buyin.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="261" data-original-width="203" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6x4vSZ3-rBhheIwbOSyLQX31jRNf49rQzVCFwrJUgmJy1xaDFyHkslU_8Y2IrHmpFY0BV9LtzM-cQu7t-98a7AmwJqkaKX32AVaQfI46r-3NRyrHWbywHvmHHR3m1ujmPEGybRtXpgJ_ZSObPy0z9grhNYD5ubVtMHjZPia7DG0uwBRGGQN8Yw7P9eQ/w156-h200/Im-not-buyin.jpg" width="156" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">I'm not buyin' it!</span></td></tr></tbody></table>I’m skeptical. In the
case of <i>Physa</i>, with which I do have a great deal of experience, even very
different penial morphologies do not preclude mating <b><span style="color: #783f04;">[7]</span></b>. There is (indeed) some prezygotic
reproductive isolation between biological species of <i>Physa</i>, but it is
behavioral (or possibly chemical) on the part of the snail mounted as
female. My personal observations do not
suggest that mechanical barriers play a significant role in interspecific
copulation in gastropods.<p></p><p>And besides. Anybody
who has walked through the weeds by a pond on a warm summer night, or hell,
anybody who has a friend with a male dachshund, you all know. Males will do it with anything. Coke bottles.
It just does not matter.</p><p class="MsoNormal">So, both Bob’s 1995 description of <i>P. gibba</i> and his 1998
description of <i>P. vinyardi </i>were published absent any genetic data, before he
met Hsiu-Ping.<span style="mso-spacerun: yes;"> </span>Between 2003 and 2008 Bob
and Hsiu-Ping did, however, publish mitochondrial CO1 gene sequences for three
individual <i>P. gibba</i> and one <i>P. vinyardi</i> <b><span style="color: #783f04;">[9]</span></b>.<span style="mso-spacerun: yes;">
</span>And it materialized that <i>gibba</i> and <i>vinyardi</i> are very similar
genetically, mtDNA percent sequence divergence ranging just 0.5% to 1.1%.</p><p class="MsoNormal">All of which now brings us back up to the dark days of May
2020, and my email exchange with Hsiu-Ping.
Hsiu-Ping explained to me that she had recently agreed to provide
molecular identifications for a set of 21 <i>Pyrgulopsis</i> samples <b><span style="color: #783f04;">[10]</span></b> collected
from northern Nevada by Ms. Diana Eck of the environmental consulting firm,
Stantec. And that she had sequenced the
CO1 gene from approximately 4 – 6 individuals from each population, for a total
sample size of N = 88. The Baysian tree
below shows the N = 29 unique CO1 haplotypes Hsiu-Ping discovered, with
unidentified population number (“unk”), setting aside duplicates. Also shown are the three control <i>P. gibba</i>
sequences from GenBank, and the one control <i>P. vinyardi</i>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlEFtIIqeb4k7JelVQP_aq1ggcs3ob0amHWFjGt7RhdMAt32-UvLWMzOxoKURYcc63l_Pn9XwzuLPvA8RttYXifaYvcTo4IQjk0oH9bgFrMXba3zFY9scDnCgA0LK_KI3EDAQog-_aKn3lriI6oEM_ubBEDSqm5Cmu6qteaxqPJriD_PCU9xWbXqo3Ow/s850/Liu-tree-18may22.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="850" data-original-width="649" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlEFtIIqeb4k7JelVQP_aq1ggcs3ob0amHWFjGt7RhdMAt32-UvLWMzOxoKURYcc63l_Pn9XwzuLPvA8RttYXifaYvcTo4IQjk0oH9bgFrMXba3zFY9scDnCgA0LK_KI3EDAQog-_aKn3lriI6oEM_ubBEDSqm5Cmu6qteaxqPJriD_PCU9xWbXqo3Ow/s320/Liu-tree-18may22.jpg" width="244" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">CO1 sequence diversity in N. Nevada <i>Pyrgulopsis</i></span></td></tr></tbody></table><p class="MsoNormal">So, the second branch of the tree does indeed divide the
control <i>vinyardi</i> from the control <i>gibba</i>, as one might expect. But look at the samples from unidentified
population #22, collected 23 miles NE of Lovelock, Nevada. Sequences 22-A and 22-B cluster with
<i>vinyardi</i>, while sequence 22-C clusters with <i>gibba</i>! Could this be evidence that Spring #22 is
inhabited by both <i>P. gibba</i> and <i>P. vinyardi</i>?
And that the two populations demonstrate reproductive isolation in
sympatry? My knowledge of the vast and
weighty literature is far from encyclopedic, but I cannot recall any case of
sympatric <i>Pyrgulopsis</i> species ever previously documented in the American West.</p><p class="MsoNormal">Hsiu-Ping and I resolved to test population #22 for
character phase disequilibrium <b><span style="color: #783f04;">[11]</span></b>. And
so it came to pass that in June of 2020 a fresh sample of <i>Pyrgulopsis</i> collected
from population #22 arrived on my doorstep, courtesy of Ms. Eck. My half of the study was to dissect these
snails and characterize their penial morphology as either matching <i>P. vinyardi</i>
or matching <i>P. gibba</i>. Then sending the
residual tissues to Hsiu-Ping, she would characterize the individuals as either
matching <i>vinyardi</i> or matching <i>gibba</i> by their CO1 gene sequence. A significant relationship between penial
morphology and CO1 sequence would suggest reproductive isolation within the
sample, confirming the specific distinction between <i>vinyardi</i> and <i>gibba</i>.</p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCwBV6hBK1iopDixR0fgutuTaylOi5d7v6upmeg3hEczu_eZXYj8_DVDICZV_BXj7OrGdmOlbvLCtvOIBMVYCroPJgvlf6FXMeZ9tqhF2gVfYDFY6gt7HIbIqOhdJMtbVxctlpMZKehaQ4La5Nk0u8xqHK-Ty5rqMhVxCZ5s4c32MQkVU5lBQK6F9qhQ/s640/P_gibba32-scale.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="640" data-original-width="640" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCwBV6hBK1iopDixR0fgutuTaylOi5d7v6upmeg3hEczu_eZXYj8_DVDICZV_BXj7OrGdmOlbvLCtvOIBMVYCroPJgvlf6FXMeZ9tqhF2gVfYDFY6gt7HIbIqOhdJMtbVxctlpMZKehaQ4La5Nk0u8xqHK-Ty5rqMhVxCZ5s4c32MQkVU5lBQK6F9qhQ/w200-h200/P_gibba32-scale.jpg" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Pyrgulopsis from Site 22</span></td></tr></tbody></table><p class="MsoNormal">And so, I went to work with tiny forceps and even tinier
dissecting needles, cracking and dissecting 30 adults <b><span style="color: #783f04;">[12]</span></b>, identifying 15
females and 15 males. I ignored dg3,
which is an unreliable character. Then
five males demonstrated both dg1 and dg2, matching <i>P. vinyardi</i>. Three males did not demonstrate either dg1 or
dg2, matching <i>P. gibba</i>. And seven males
demonstrated either dg1 or dg2, intermediate between <i>gibba</i> and <i>vinyardi</i>. And in July of 2020 I forwarded 15 little
tubes onward to Hsiu-Ping, 5 marked G for <i>gibba</i>, 3 marked V for <i>vinyardi</i>, and 7
marked I for intermediate.</p><p class="MsoNormal">The Baysian tree below shows Hsiu-Ping’s results for 13 of
the 15 snails I dissected (setting aside 2 duplicate sequences), plus all five
of the sequences she obtained from Ms. Eck’s original sample, plus the four
control sequences from GenBank.
Hsiu-Ping’s analysis did resolve two sort-of distinct clusters of CO1
sequence within population #22, but those two clusters did not correspond to
penial morphology, nor indeed, did they correspond especially well to the four
CO1 sequences previously deposited in GenBank, three from nominal <i>gibba </i>and one
from nominal <i>vinyardi</i>. There is no
pattern in the distribution of samples labelled G, V, and I.</p><p class="MsoNormal">Hence there is no evidence of character-phase disequilibrium
between penial morphology and CO1 sequence in <i>Pyrgulopsis</i> population #22. Hence there is no evidence of reproductive
isolation between <i>P. gibba</i> and <i>P. vinyardi</i>.
The gray-literature report we filed with Ms. Eck on 22Oct21, available
for download as FWGNA Circular #6 from footnote <b><span style="color: #783f04;">[1]</span></b> below, concluded “that <i>P.
gibba</i> and <i>P. vinyardi</i> should be synonymized into one species.” My buddy Bob’s (1995) <i>gibba</i> would have
priority over his (1998) <i>vinyardi</i>.</p><p class="MsoNormal"><o:p></o:p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpwJ4-XT1ZBNV48McM3j1jibtwf_7oSWyG4RS1-dH6Jat2M4Njm1737_qv_yxVa2Fv_7ABIobA2PdHU1fuwwy9iH66WMnG9AfWPh_Z7X2pUgSgeMgqUvKuAV4rKH858yyqaUmKW0ibJVay5YO8HVf5Kf9xrKUyFbXOVZ7vNPTbLEva-pEJDP6PaMjpRA/s2799/Liu-Dillon-vinyardi-tree.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2799" data-original-width="2056" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpwJ4-XT1ZBNV48McM3j1jibtwf_7oSWyG4RS1-dH6Jat2M4Njm1737_qv_yxVa2Fv_7ABIobA2PdHU1fuwwy9iH66WMnG9AfWPh_Z7X2pUgSgeMgqUvKuAV4rKH858yyqaUmKW0ibJVay5YO8HVf5Kf9xrKUyFbXOVZ7vNPTbLEva-pEJDP6PaMjpRA/s320/Liu-Dillon-vinyardi-tree.jpg" width="235" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From Liu & Dillon <b><span style="color: #783f04;">[1]</span></b></span></td></tr></tbody></table><p class="MsoNormal">OK, I know that’s a lot of technical detail for a silly,
frivolous blog post. So come back up to
the surface with me and let’s take a big, fresh breath of air together. Look at those two little shells I figured at
the top of this essay, and then look at those four sets of penis diagrams four column inches below. <b>Both of the shells
figured above, and all of those penises, were borne by a single biological
species of <i>Pyrgulopsis</i></b>.</p><p class="MsoNormal">I should conclude this essay, however, emphasizing once
again that science is the construction of testable hypotheses about the natural
world. Science is not right, it is
testable. And over the course of a
distinguished career spanning almost 40 years, my buddy Bob rigorously
constructed 126 testable hypotheses about the <i>Pyrgulopsis</i> fauna of the great
American West. One day, I feel sure,
somebody will come behind him and test the 125 that remain. I cannot imagine
when, or by whom. Not it.</p><p class="MsoNormal"><br /></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Liu, H-P, and R. T. Dillon, Jr. (2021) Resolving the
species status of Surprise Valley Pyrg (<i>Pyrgulopsis gibba</i>) and Vineyard Pyrg
(<i>Pyrgulopsis vinyardi</i>). Report to
Stantec Environmental Consulting. FWGNA Circular 6: 1 – 5. [<a href="https://www.fwgna.org/downloads/FWGNA-Circular-6.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> Hershler, R. & H-P. Liu (2017) Annotated Checklist
of Freshwater Truncatelloidean Gastropods of the Western United States, with an
Illustrated Key to the Genera. US Bureau
of Land Management Technical Note 449: 1 – 142.</p><p class="MsoNormal"><b><span style="color: #783f04;">[3] </span></b>We always used pine cones when I was growing up, too
poor for corn cobs.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4] </span></b>Hershler R. 1995. New freshwater snails of the Genus
<i>Pyrgulopsis</i> (Rissooidea: Hydrobiidae) from California. The Veliger 38(4):
343-373.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Hershler R. 1998. A systematic review of the hydrobiid
snails (Gastropoda: Rissooidea) of the Great Basin, western United States. Part
I. Genus <i>Pyrgulopsis</i>. The Veliger 41: 1-132.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> The boxed figure of the <i>P. vinyardi</i> penis was scanned
from figure 39 of Hershler <b><span style="color: #783f04;">[5]</span></b>, showing dorsal aspect on the left and ventral
aspect on the right. The remainder of
the figure, showing penial morphology for three different <i>P. gibba</i> males, was
scanned from figure 12 of Hershler <b><span style="color: #783f04;">[4]</span></b>.
Again, dorsal aspect on the left, ventral on the right. Abbreviations Dg = dorsal gland, Vg = ventral
gland, Tg = terminal gland, P = penial filament. The Dg3 region is encircled.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> The literature on prezygotic reproductive isolation in
<i>Physa</i> is extensive. Here’s a good entry:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Dillon, R.T., A.R. Wethington, and C. Lydeard (2011) The
evolution of reproductive isolation in a simultaneous hermaphrodite, the
freshwater snail <i>Physa</i>. BMC Evolutionary
Biology 11: 144. [<a href="https://bmcecolevol.biomedcentral.com/articles/10.1186/1471-2148-11-144" target="_blank">html</a>] [<a href="https://www.fwgna.org/dillonr/Dillon-Wethington-Lydeard.pdf" target="_blank">pdf</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Penial morphology of <i>Pyrgulopsis sadai</i>, from Hershler
<b><span style="color: #783f04;">[5]</span></b>, figure 39.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> The three CO1 sequences for <i>P. gibba</i> and the one
sequence for<i> P. vinyardi</i> were published in four different papers:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Hershler, R., Frest, T.J., Liu, H.-P., Johannes, E.J. 2003a.
Rissooidean snails from the Pit River basin, California. Veliger 46:275-304.</li><li>Hershler, R. and Liu, H.P. (2004) A molecular phylogeny of
aquatic gastropods provides a new perspective on biogeographic history of the
Snake River Region. Mol. Phylogenet. Evol. 32 (3), 927-937.</li><li>Hershler, R., Liu, H.-P. 2008. Ancient vicariance and recent
dispersal of springsnails (Hydrobiidae: Pyrgulopsis) in the Death Valley
system, California-Nevada. In: Reheis, M.C., Hershler, R., Miller, D.M., eds.
Late Cenozoic drainage history of the southwestern Great Basin and lower
Colorado River region: geologic and biotic perspectives. Geological Society of
America Special Paper 439:91-101.</li><li>Hershler, R., Liu, H.-P. and Gustafson, D.L. (2008) A second
species of <i>Pyrgulopsis</i> (Hydrobiidae) from the Missouri River basin, with
molecular evidence supporting faunal origin through Pliocene stream capture
across the northern continental divide. J. Molluscan Stud. 74 (4), 403-413.</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Ms. Eck actually sent 22 populations for analysis, but
population #11 turned out to be a lymnaeid.
So just 21 populations of <i>Pyrgulopsis</i>.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> In January of 2022 I defined character phase
disequilibrium as “any violation of independent assortment between one or more
morphological characters and one or more characters of demonstrably genetic
origin.” Although CPD can arise from any
violation of the assumption of random mating, the most likely explanation in
Spring #22 would be reproductive isolation.
See:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>What is character phase disequilibrium? [<a href="https://fwgna.blogspot.com/2022/01/what-is-character-phase-disequilibrium.html" target="_blank">4Jan22</a>]</li><li>Character phase disequilibrium in the <i>Gyraulus</i> of Europe
[<a href="https://fwgna.blogspot.com/2022/02/character-phase-disequilibrium-in.html" target="_blank">4Feb22</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[12] </span></b>Actually I messed up a few, so no count.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-49845634825409728112022-08-09T01:30:00.003-04:002023-11-23T20:04:34.433-05:00Startled by Fontigens, sort-of, I suppose<p><span style="background-color: white; color: #333333; font-family: Georgia, serif; font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b) Startled by Fontigens, sort-of, I suppose. Pp 217 – 223 </span><b style="background-color: white; color: #333333; font-family: Georgia, serif; font-size: xx-small;">in</b><span style="background-color: white; color: #333333; font-family: Georgia, serif; font-size: xx-small;"> The Freshwater Gastropods of North America Volume 6, </span><i style="background-color: white; color: #333333; font-family: Georgia, serif; font-size: xx-small;">Yankees at The Gap, and Other Essays</i><span style="background-color: white; color: #333333; font-family: Georgia, serif; font-size: xx-small;">. </span><a href="https://www.fwgna.org/publications/index.html" style="background-color: white; color: #5588aa; font-family: Georgia, serif; font-size: xx-small; text-decoration-line: none;" target="_blank">FWGNA Project</a><span style="background-color: white; color: #333333; font-family: Georgia, serif; font-size: xx-small;">, Charleston, SC.</span></p><p>It takes a lot of forbearance to follow the FWGNA Blog. I am aware of this. I break every rule of social media –
exploring arcane topics at great depth, extending the attention span of my
readership over many months. Sometimes
years. It is not uncommon for me,
your petulant host, to expect you to remember some petty anecdote or obscure
factoid that may have flickered through my brain years ago, and if you do not
remember it, scold you and assign it for homework. And then forget it, myself.</p><p>So, welcome to snail science – a gradual unfolding, a
cautious move forward, a startling, and an extended period of dormancy.</p><p>The stimulus for our gradual unfolding this month is the
publication late last year of a paper by Liu, Schroeder, Berry, and Dillon on
sequence divergence in phreatic hydrobioid snails of the genus <i>Fontigens</i>
<b><span style="color: #783f04;">[1]</span></b>. You might be forgiven if your
memory of my 2006 essay on the Springsnails of the Blue Ridge is a bit
fuzzy. But I do trust that you remember
our three-part series on Lori Schroeder’s tiny snails back in 2017, yes? And surely, our July 2019 report of the
discovery of a single putative <i><a href="https://www.fwgna.org/species/hydrobiidae/f_cryptica.html" target="_blank">Fontigens cryptica</a></i> in a spring at the Bernheim
Forest in central Kentucky is fresh on your mind. And you must have read my Bob Hershler
tribute last month, right? Don’t tell me
that you didn’t.</p><p>So all told, that’s six essays on <i>Fontigens</i>, written over a
span of 16 years, with which I expect you to be familiar, before going forward
into the blog post below. What, no? Tut-tut!
See note <b><span style="color: #783f04;">[4]</span></b> below for your homework assignment.</p><p>Moving forward now, cautiously. Down toward the bottom of my essay of
[<a href="https://fwgna.blogspot.com/2019/07/finding-fontigens-cryptica.html" target="_blank">3July19</a>] I wrote, “together Hsiu-Ping (Liu) and I worked up a small proposal
to the Bernheim Board for a study on the evolution of Fontigens across the
eastern USA.” I am here pleased to
report that our proposal was funded just two weeks after that essay was posted,
and that we subsequently sampled 13 additional populations of <i>Fontigens</i> beyond
the singleton putative <i>F. cryptica</i> that kicked off our research effort, and
that the results are startling, on a malacological scale, sort-of, I suppose.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEind_BwkLqq_DF6-03HkuUpgvcwMGmsPyqlZTGflFOFKzld__Ux4qmxKgbBYWjBGr_9ZpROx3JAf26LQewzjZ8ClY2Uk5LbX5mAWE6IMWFnrrH4yNV05sZm9aQZv5YBcao7FCUAIW3c5PnAzZgEIraVByaOvCurWOtcjHj0LN1-_m3kMqVBJoIEYBSpyA/s640/F_nickliniana31-BlowingSprings-scale.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="640" data-original-width="640" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEind_BwkLqq_DF6-03HkuUpgvcwMGmsPyqlZTGflFOFKzld__Ux4qmxKgbBYWjBGr_9ZpROx3JAf26LQewzjZ8ClY2Uk5LbX5mAWE6IMWFnrrH4yNV05sZm9aQZv5YBcao7FCUAIW3c5PnAzZgEIraVByaOvCurWOtcjHj0LN1-_m3kMqVBJoIEYBSpyA/w200-h200/F_nickliniana31-BlowingSprings-scale.jpg" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Topotypic <i>F. nickliniana</i> (Font14)</span></td></tr></tbody></table><p>Hsiu-Ping and I settled on a study of sequence divergence in
the mitochondrial CO1 gene quite early in our study. But as I have emphasized many times, indeed
as many as the 18 posts currently indexed at the margin of this blog under
“Gene trees,” molecular phylogenies are dependent variables, not independent variables. By themselves, they are at best weak, null
models of population relationship. Only
the scientist who brings with him a hypothesis regarding the evolution of a
group of organisms can understand a gene tree that might be derived from that
evolutionary process.</p><p>Thank heaven, then, that the 1990 monograph by Hershler,
Holsinger, and Hubricht on the North American <i>Fontigens</i> has been sitting at the
front of the thick Hershler file in my reprint cabinet for thirty years
<b><span style="color: #783f04;">[5]</span></b>. Last month [<a href="https://fwgna.blogspot.com/2022/07/my-buddy-bob.html" target="_blank">6July22</a>] I sang the
praises of that wonderful work – complete, scholarly, detailed, and unsullied
by any taint of molecular phylogenetics.
Entirely upon the basis of morphological data, demonstrating a
remarkable appreciation for both intrapopulation and interpopulation variation,
my buddy Bob recognized nine species of <i>Fontigens</i> in North America, plus <i>F.
cryptica</i> of “uncertain status.” I cannot
imagine any finer standard against which to calibrate a gene tree such as the
one Hsiu-Ping and I proposed to construct.</p><p>So, the late summer of 2019 found me cruising along the Blue
Ridge of Old Virginia, very much as I described in my essay of [<a href="https://fwgna.blogspot.com/2006/07/springsnails-of-blue-ridge.html" target="_blank">26July06</a>]. And as my idyllic journey unfolded, I paused
to collect three of the many populations of <i><a href="https://www.fwgna.org/species/hydrobiidae/f_orolibas.html" target="_blank">Fontigens orolibas</a></i> Bob Hershler
catalogued in his monograph. These
included Leslie Hubricht’s (1957) type locality at Hawksbill Spring (Font17),
beside the Appalachian Trail at northbound mile 930.5, a prettier habitat it is
difficult to imagine. And I sampled a
second<i> F. orolibas</i> population (Font18) just 80 km south on the Blue Ridge
Parkway at the pioneer springhouse figured in my 2006 post. And our good friends Wil Orndorff and Tom
Malabad of the VaDCR contributed a third population of <i>F. orolibas</i> from Hugh
Young Cave (Font19), 250 km further SW, to slide the scale. </p><p>And ditto for <i><a href="https://www.fwgna.org/species/hydrobiidae/f_nickliniana.html" target="_blank">Fontigens nickliniana</a></i>. Although Isaac Lea’s (1838) type locality for
“<i>Paludina” nickliniana</i> (Hot Springs, Virginia) is obscure, I felt as though a
sample from Blowing Springs (about 9 km N of Hot Springs) could reasonably
substitute (Font14). Then I added a
second population of <i>F. nickliniana </i>listed by Bob Hershler 140 km NE at Lantz
Mills, VA, (Font15), and a third population about 250 km SW at Fleenor Spring,
VA, (Font16). To these samples Hsiu-Ping
was gratified to contribute an individual <i>F. nickliniana</i> she found in her
freezer from Indiana (Font3). And you
might remember, but are excused if you do not, that as of 2019, GenBank already
held exactly one CO1 sequence for any <i>Fontigens </i>whatsoever, that of <i>Fontigens
nickliniana</i>, an individual collected in Michigan <b><span style="color: #783f04;">[6]</span></b>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiT8CgrxygnTN-6x02EJiPxz7_p_3yehkE116UjEtk36dPfSn8JRrb47YGEYo2sZ3MLP5wbTVbT4bMDVhhCU6pSrtqVWAn9K3u9ZriVBiGpv2qTszBgQl_vwqhCKfo4a84-YhBghh0yPkHwKuuzGPKMW2GvoQF1xITu1FtptBqP1PsPaKHQlmkilANvlg/s640/blowing-spring.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="480" data-original-width="640" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiT8CgrxygnTN-6x02EJiPxz7_p_3yehkE116UjEtk36dPfSn8JRrb47YGEYo2sZ3MLP5wbTVbT4bMDVhhCU6pSrtqVWAn9K3u9ZriVBiGpv2qTszBgQl_vwqhCKfo4a84-YhBghh0yPkHwKuuzGPKMW2GvoQF1xITu1FtptBqP1PsPaKHQlmkilANvlg/w320-h240/blowing-spring.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Blowing Springs, VA <b><span style="color: #783f04;">[7]</span></b></span></td></tr></tbody></table><p>I was also able to sample the type locality of <a href="https://www.fwgna.org/species/hydrobiidae/f_morrisoni.html"><i>Fontigens morrisoni</i></a> on my 2019 field trip through the green rolling hills of Old Virginia
(Font13). Hsiu-Ping had samples in her
freezer from the type localities of <a href="https://www.fwgna.org/species/hydrobiidae/f_tartarea.html" target="_blank"><i>F. tartarea</i></a> (Font1) and <a href="https://www.fwgna.org/species/hydrobiidae/f_bottimeri.html" target="_blank"><i>F. bottimeri</i></a>
(Font6), and our colleague Bob Weck sent us samples from the type locality of
<i>F. antroecetes</i> in Illinois (Font22). And
our good friends Wil and Tom contributed a second population of <i>F. bottimeri</i>
sampled from Ogden’s Cave about 100 km W of the type locality (Font11). Comparison to the genetic diversity
demonstrated by these 13 carefully-chosen populations (plus the singleton
sequence from GenBank) should, we felt, allow us to place the CO1 sequence
divergence demonstrated by our single putative <i>F. cryptica</i> individual from
Kentucky (Font12) into its proper evolutionary context.</p><p>A neighbor-joining gene tree based on our CO1 results is
shown below <b><span style="color: #783f04;">[8]</span></b>. And the most striking
result of our analysis was, without question, the tremendous mtDNA sequence
divergence we discovered among conspecific populations. Sequence variation within the Blowing Springs
type population of <i>F. nickliniana</i> (Font14) was negligible, for example, and ditto within Font16
from Fleenor Spring, and ditto within Font15 from Lantz Mills – just a few
nucleotides. But in striking contrast,
the mean between-population sequence divergence was 10.8% between Font14 and
Font16, 10.4% between Font15 and Font16, and 11.0% between Font14 and Font15.</p><p>Similarly negligible values of sequence variation within
populations, contrasted with strikingly-high sequence variation between
conspecific populations, prevailed across our entire control sample of six
<i>Fontigens</i> species. Mean interpopulation
sequence divergence reached as high as 14.3% between the <i>F. orolibas</i> inhabiting
the Hawksbill Spring type locality (Font17) and Hugh Young Cave (Font19).</p><p>This situation was so reminiscent of the population genetics
characteristic of pleurocerid snails <b><span style="color: #783f04;">[9]</span></b> that I suggested to Hsiu-Ping we might
want to look for mitochondrial superheterogeneity within our three<i> F.
nickliniana </i>populations. We upped our
samples sizes to 30 for Font14, 10 for Font15 and 10 for Font16, but didn’t
find any.</p><p>The levels of interpopulation mtDNA sequence divergence we
discovered within species did not, however, swamp out divergence between the
species. The mean CO1 divergence among
species ranged from a high of 21.0% (between <i>F. nickliniana</i> and <i>F. morrisoni</i> of
Virginia) to a low of 8.7% (between Virginia <i>F. bottimeri</i> and Illinois <i>F.
antroecetes</i>).</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEx5Pabm00pSBukVv-n7qOrScEyXBVxrITfiyoWcB8U0jfL7wqSv6gSBbPz97ZjrNp7MpdycrftISE2KXrhNUIolBycEr_3nR_Y8qpKHUHc_-NoUc0bjNNhGODVmNdbse0oxWcwcqYFElerFNtURAppI2Y_k8ke-gg0t9H7S-7Ib2mTHP0Uayok0YB0A/s992/Fontigens-NJ-tree.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="992" data-original-width="622" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEx5Pabm00pSBukVv-n7qOrScEyXBVxrITfiyoWcB8U0jfL7wqSv6gSBbPz97ZjrNp7MpdycrftISE2KXrhNUIolBycEr_3nR_Y8qpKHUHc_-NoUc0bjNNhGODVmNdbse0oxWcwcqYFElerFNtURAppI2Y_k8ke-gg0t9H7S-7Ib2mTHP0Uayok0YB0A/w251-h400/Fontigens-NJ-tree.jpg" width="251" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">NJ tree from CO1 sequence</span></td></tr></tbody></table><p>Our second-most striking result was the nesting of the two
<i>F. nickliniana</i> sequences we analyzed from the Midwest, Font3 from Indiana and
JX970609 from Michigan, within our Font15 cluster from Lantz Mills,
Virginia. I admit that I do not have as
much experience pioneering through forests of gene trees as most of my
colleagues. But this is the clearest
example of a “shared primitive” mtDNA sequence I have ever seen. Cladists made up the term “symplesiomorphy”
to describe this phenomenon and used it for tails on fish.</p><p>And finally. The only
unknown sample hanging on our entire tree was Lori Schroeder’s tiny snail, Font12,
the singleton individual that she and Andrew Berry discovered under that rock
at the springhead in the Bernheim Forest back in 2019. The minimum mean CO1 sequence divergence
between that little snail and any of the control <i>Fontigens</i> species in our study
was 14.4%, with <i>F. bottimeri </i>of Virginia.
Thus, our hypothesis that Lori’s snail was sampled from a distinct
species is confirmed. And since the shell
and the animal both match Leslie Hubricht’s (1963) description of <i>Fontigens
cryptica</i> <b><span style="color: #783f04;">[10]</span></b>, it is <i>F. cryptica</i>.</p><p>The confirmation that a population of <i>Fontigens cryptica</i>
inhabits the subterranean waters of central Kentucky is not surprising, I don’t
suppose, especially after five years of breathless advertisement in the columns
of this blog. But the <b>high levels of
interpopulation mtDNA sequence divergence</b> we documented across the genus
<i>Fontigens</i> on the way to that unsurprising conclusion, my goodness!</p><p>Twenty years of published research on hydrobioid evolution
in the American West led us to expect much less than 1% divergence between
conspecific populations. Bob and
Hsiu-Ping haven’t typically documented much more than a couple percent CO1
sequence difference among their scores of newly-described species. But in Virginia, even a very small sample of
three <i>F. orolibas</i> populations returned interpopulation sequence divergences as
high as 14.3%! Has the evolution of
hydrobioid populations in isolated springs of the American West been so very
different from the hydrobioids inhabiting isolated springs of the American East? Startling, indeed.</p><p><br /></p><p><u>Notes</u></p><p>[1] Liu, H-P., L. Schroeder, A. Berry, and R.T. Dillon, Jr.
(2021) High levels of mitochondrial DNA sequence divergence among isolated
populations of <i>Fontigens</i> (Truncatelloidea: Emmericiidae) <b><span style="color: #783f04;">[2]</span></b> in eastern USA.
Journal of Molluscan Studies 87. [<a href="https://www.fwgna.org/dillonr/Liu-etal-2021.pdf" target="_blank">PDF</a>]
[<a href="https://academic.oup.com/mollus/article-abstract/87/3/eyab026/6354584?redirectedFrom=fulltext&login=false" target="_blank">html]</a></p><p><b><span style="color: #783f04;">[2]</span></b> No, the genus <i>Fontigens</i> has not properly been assigned
to the family Emmericiidae since 2013 <b><span style="color: #783f04;">[3]</span></b>.
The parenthetical material was added to our title by some clueless naïf
in the editorial office of the journal.</p><p><b><span style="color: #783f04;">[3]</span></b> Wilke T., Haase M., Hershler R., Liu H-P., Misof B.,
Ponder W. (2013) Pushing short DNA
fragments to the limit: Phylogenetic relationships of “hydrobioid” gastropods
(Caenogastropoda: Rissooidea). Molecular
Phylogenetics and Evolution 66: 715 – 736.
For a review, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The Classification of the Hydrobioids [<a href="https://fwgna.blogspot.com/2016/08/the-classification-of-hydrobioids.html" target="_blank">18Aug16</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Here is your homework assignment. Yes, this will be on the test. All of it:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Springsnails of the Blue Ridge [<a href="https://fwgna.blogspot.com/2006/07/springsnails-of-blue-ridge.html" target="_blank">26July06</a>]</li><li>Lori Schroeder’s tiny snails [<a href="https://fwgna.blogspot.com/2017/07/lori-schroeders-tiny-snails.html" target="_blank">17July17</a>]</li><li>The most cryptic freshwater gastropod in the world [<a href="https://fwgna.blogspot.com/2017/08/the-most-cryptic-freshwater-gastropod.html" target="_blank">6Aug17</a>]</li><li>Not finding Fontigens cryptica [<a href="https://fwgna.blogspot.com/2017/09/not-finding-fontigens-cryptica.html" target="_blank">6Sept17</a>]</li><li>Finding Fontigens cryptica [<a href="https://fwgna.blogspot.com/2019/07/finding-fontigens-cryptica.html" target="_blank">3July19</a>]</li><li>My buddy Bob [<a href="https://fwgna.blogspot.com/2022/07/my-buddy-bob.html" target="_blank">6July22</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Hershler, R., J.R. Holsinger & L. Hubricht (1990) A
revision of the North American freshwater snail genus <i>Fontigens</i> (Prosobranchia:
Hydrobiidae). Smithsonian Contributions to Zoology 509: 1-49.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> In my essay of [<a href="https://fwgna.blogspot.com/2016/08/the-classification-of-hydrobioids.html" target="_blank">18Aug16</a>] I mentioned that “a <i>Fontigens
nicklinian</i>a sample from Michigan” was the only fontigentine included in the
gigantic worldwide CO1+16S+18S gene tree of Wilke and colleagues <b><span style="color: #783f04;">[3]</span></b>.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Air exactly 58
degrees F blows out of pipes set in the mountainside above the spring, 365
days per year. I don’t know why.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Lori showed this gene tree in a talk she gave at the
OVUM meeting in 2019. A couple notes
might be helpful for those of you comparing the 2019 tree to the one we published
as Figure 2 in our paper <b><span style="color: #783f04;">[1]</span></b>. We changed
our population codes slightly between 2019 and 2021, so that Font14 became “nic14”
and Font17 became “oro17” and so forth.
And the figure in our published paper was a Baysian tree, rather than
simple neighbor-joining. And we added a
couple additional outgroups from GenBank.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> The phenomenon of double-digit mtDNA intrapopulation sequence variation is so common in pleurocerid populations that I have coined the term "mitochondrial superheterogeneity" to describe it. For a review, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Mitochondrial superheterogeneity: What we know [<a href="https://fwgna.blogspot.com/2016/03/mitochondrial-superheterogeneity-what.html" target="_blank">15Mar16</a>] </li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Hubricht, L. (1963)
New species of Hydrobiidae. Nautilus
76: 138 - 140.</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-47736636820364546192022-07-06T09:08:00.001-04:002023-11-23T19:55:34.561-05:00My buddy, Bob<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as:
Dillon, R.T., Jr. (2023b) My Buddy, Bob. Pp 203 – 210 <b>in</b> The
Freshwater Gastropods of North America Volume 6, <i>Yankees at The Gap, and Other
Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p class="MsoNormal"><o:p></o:p></p><p>Although we studied at different institutions, Bob Hershler
was my best friend in graduate school. He was enrolled at Johns Hopkins way down in
Baltimore, and I at the University of Pennsylvania in Philadelphia. But we shared George Davis as our major
advisor, so for several years we both spent most of our hours many of our days
in the Malacology Department at the Academy of Natural Sciences.</p><p>In many ways, Bob was closer to George than I was,
ultimately completing his dissertation on a morphological study of an endemic
radiation of hydrobioids in northern Mexico <b><span style="color: #783f04;">[1]</span></b>, really rather similar to
George’s masterpiece in southeast Asia<b><span style="color: #783f04;"> [2]</span></b>.
Meanwhile, I was in the lab running allozyme gels on the opposite of an
endemic radiation in the American pleurocerids <b><span style="color: #783f04;">[3]</span></b>.</p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGruDaUsEE0o2qHbRETx-PUJwrnRIw_1etWcwQ9uAIR6j4qZax7qpjUD8yqqNHgi5-fUuhvN5OH7HwfqsfpshIcGnv0Dc3o07-gPJTWWFSybDKEZMdHRN8NlWhR7gbvrgZEHQjOSOyGJwMjycYhGeCErXZ_ujU9aNr-TricOR2G2K6l8FZ6jzwxs2LNQ/s823/Rob&Bob1977.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="823" data-original-width="823" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGruDaUsEE0o2qHbRETx-PUJwrnRIw_1etWcwQ9uAIR6j4qZax7qpjUD8yqqNHgi5-fUuhvN5OH7HwfqsfpshIcGnv0Dc3o07-gPJTWWFSybDKEZMdHRN8NlWhR7gbvrgZEHQjOSOyGJwMjycYhGeCErXZ_ujU9aNr-TricOR2G2K6l8FZ6jzwxs2LNQ/w200-h200/Rob&Bob1977.jpg" width="200" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Rob & Bob in Philadelphia, 1977</span></td></tr></tbody></table><p class="MsoNormal">Bob often slept on the carpet under the big table in the
malacology library. And there was a
night watchman, stationed at the desk at a side door downstairs, who patrolled
regular rounds inside the building. The
watchman knew Bob was sleeping under there, which he most certainly was not
supposed to be doing, but nevertheless turned a blind eye.</p><p class="MsoNormal">One evening Bob was running a set of exploratory
electrophoresis gels, and after he got his samples on, decided to go out for
supper. And he walked by the watchman at
the side door and out onto 19th Street and was gone for perhaps an hour or
so. And when he returned to the 19th
Street door, the watchman was on his rounds.
And the door was locked.</p><p class="MsoNormal">And Bob panicked.
Fearing that his gels would cook and might ultimately (I suppose?) start
a fire, he pulled the fire alarm on the side of the building. I will leave to your imagination what
response might follow a fire alarm at a 150-year-old building crammed with
rotten alcohol and animal skins in downtown Philadelphia in the middle of the
night.</p><p class="MsoNormal">Bob was awarded his Ph.D. in 1983, the same year that I was
awarded mine, and by the blessing of divine providence, was able to win a
curatorial position at the U.S. National Museum a couple years later. Such plums are few and far between for
scientists with our very specialized (and quite possibly obsolete)
backgrounds. My self-effacing buddy Bob
confided to me shortly thereafter, “It was a weak field” <b><span style="color: #783f04;">[4]</span></b>.</p><p class="MsoNormal">But at the USNM Smithsonian, Bob’s career flourished. His research focused almost entirely on the
hydrobioids, of which he became the unchallenged North American authority,
publishing over 100 peer-reviewed papers, many monographic in their size and
scope. His malacology was neoclassical,
featuring lovely, detailed drawings of the dissected animals themselves, in the
style of a Henry Pilsbry or our shared mentor George. But he often whistled modern notes. At his best, Bob was able to recognize
intrapopulation and interpopulation variation along with the most evolutionary
of his contemporaries. His unification
of <i>Pyrgulopsis robusta</i>, for example, will have a lasting impact <b><span style="color: #783f04;">[6]</span></b>.</p><p class="MsoNormal">The 1990 monograph of the phreatic genus <i>Fontigens</i> he
published with John Holsinger and Leslie Hubricht <b><span style="color: #783f04;">[7]</span></b> was a thing of
beauty. It opens with a marvelous and
detailed examination of morphological variation in the most common species,
<i><a href="https://www.fwgna.org/species/hydrobiidae/f_nickliniana.html" target="_blank">Fontigens nickliniana</a></i>, depicting shells of all shapes and penial complexes of
in all their elaborate forms and twisted wonder. His section subtitled “material examined”
lists hundreds of distinct springs and spring runs in ten different states
where populations of <i>F. nickliniana</i> can be found, with locality data of
sufficient quality so that any subsequent worker can go and look at the things
himself, if he has any questions. That’s
the best part of the monograph.</p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkZdCi020OlqZcMWfFc9V4wSttlx9ajsd1h1B0jsL4t1v_HYuiSJhHJChCGJFfbtePeB4egUoc6u3h_M3LxM8YSActWUVJ8n0a5XPpNhApEpnJHeP4dLJl4Iu9-r-b1NGq9NshRyLpXwt3An44monrPtw3X4kQDSvXy06O8BBHW4SCPwjvn4qj1AAzMg/s1810/hershler-1990-fig7.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1810" data-original-width="1052" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkZdCi020OlqZcMWfFc9V4wSttlx9ajsd1h1B0jsL4t1v_HYuiSJhHJChCGJFfbtePeB4egUoc6u3h_M3LxM8YSActWUVJ8n0a5XPpNhApEpnJHeP4dLJl4Iu9-r-b1NGq9NshRyLpXwt3An44monrPtw3X4kQDSvXy06O8BBHW4SCPwjvn4qj1AAzMg/s320/hershler-1990-fig7.jpg" width="186" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>F. nickliniana </i>penis variation <b><span style="color: #783f04;">[8]</span></b></span></td></tr></tbody></table><p class="MsoNormal">Then moving forward from a rock-solid understanding of
morphological variation in <i>Fontigens nickliniana</i>, Bob proceeded by rigorous
methodology to distinguish nine additional species in the genus. Four of these are more or less sympatric with
<i>nickliniana</i> in the Valley-and-Ridge Province of Virginia, most strikingly <i><a href="https://www.fwgna.org/species/hydrobiidae/f_orolibas.html" target="_blank">F. orolibas</a></i>, which even co-occurs mixed with <i>F. nickliniana</i>, lending credence to
the hypothesis of reproductive isolation.
Again, Bob offers lovely figures of shell, radula, and reproductive
anatomy for each, with excellent locality data.
And he iced the cake with a dichotomous key to cleanly distinguish among
the ten total. This work is easily on
par with that of a Hubendick or a Meier-Brook <b><span style="color: #783f04;">[9]</span></b>. Bob’s 1990 <i>Fontigens</i> monograph is as good as
classical malacology ever got or can get.</p><p class="MsoNormal">Almost as good, equally important, and even larger was his
1994 monograph on the North American <i>Pyrgulopsis</i> <b><span style="color: #783f04;">[10]</span></b>. I keep a copy by my desk and refer to it
often. In this 115-page tour-de-force
Bob recognized 11 <i>Pyrgulopsis </i>species from Eastern North America as well as the
54 that (by that early date) had been described from the American West. Of the 54, Hershler had himself described
21. We will have much more to say about
both the Eastern subset (now referred to <i>Marstonia</i>) and the western subset
(still <i>Pyrgulopsis</i>) in coming months.</p><p class="MsoNormal">I think it is fair to say, by a margin of approximately 54
to 11, that Bob’s greatest love was his first love – the hydrobioid fauna of
the American West. Running my finger
through the “Annotated Checklist of Freshwater Truncatelloidean Gastropods of
the Western United States” he published with Hsiu-Ping Liu in 2017 <b><span style="color: #783f04;">[11]</span></b>, I
count 43 papers with Hershler as the senior author, including such major
contributions as the (63 pg) review of the Arizona hydrobiids he published in
1988, his (140 pg) Cochliopine monograph of 1992, his second (132 pg)
<i>Pyrgulopsis</i> monograph of 1998, his (41 pg) <i>Fluminicola</i> monograph of 1996, and
his (53 pg) <i>Tryonia</i> monograph of 2001<b><span style="color: #783f04;"> [12]</span></b>.</p><p class="MsoNormal">From his hypotheses regarding evolutionary relationships
among western hydrobioid populations he developed a secondary interest in
biogeography, publishing reconstructions of ancient drainage systems <b><span style="color: #783f04;">[13]</span></b>. He had little interest in population biology,
ecology, or the broader malacofauna beyond the hydrobioids, however. When I approached him about collaborating on
the FWGNA project back in 1998, he replied, “I don’t do checklists” <b><span style="color: #783f04;">[14]</span></b>.</p><p class="MsoNormal">It should not surprise you, after having read the anecdote
with which this essay opened, that Bob did not run any sort of genetic
laboratory. But in 1999 he developed a
tremendously productive relationship with someone who did, Dr. Hsiu-Ping Liu,
and for 20 years they made beautiful malacological music together. Of the 43 papers on the western hydrobioids I
counted above, 30 were published after 1998, and of those 30, Hsiu-Ping is also
listed as an author on 26. In addition,
the Literature Cited section of the Hershler & Liu catalog also includes 10
papers with Hsiu-Ping as lead author, Bob’s name following.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1SvauiUSMgCyShkLp-a9bSPGFme0kQKKII9p2BmLtRqugpxudYRwC2-6zdm3sf_xMhEkiL5ZxEF7EWJNIOg3TE408Nen_2nQ-_3XhNzBPaLIMquOJmbR_4nGE2BotH1MKNZt-aJrMlCcnFXe_Z7OIV_psFmDd6MQLe7j9wwK3rW9OL4OxmCep9oM9aw/s1058/Hershler-1994-fig2.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="580" data-original-width="1058" height="175" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1SvauiUSMgCyShkLp-a9bSPGFme0kQKKII9p2BmLtRqugpxudYRwC2-6zdm3sf_xMhEkiL5ZxEF7EWJNIOg3TE408Nen_2nQ-_3XhNzBPaLIMquOJmbR_4nGE2BotH1MKNZt-aJrMlCcnFXe_Z7OIV_psFmDd6MQLe7j9wwK3rW9OL4OxmCep9oM9aw/s320/Hershler-1994-fig2.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;"><i>Pyrgulopsis</i> penis from Hershler <span style="color: #783f04;"><b>[15]</b></span></span></td></tr></tbody></table>Alas, the rising tide of mtDNA sequence data that began to
slosh across Bob’s desk in the 2000s pushed his species concept in a more
typological direction, as became common in the generation that followed
us. How many species did he ultimately
describe? I do not know. Bob and Hsiu-Ping’s 2017 catalog listed 126
species of <i>Pyrgulopsis</i> inhabiting the waters of the Western United States, 107
of which (I count) Bob Hershler was the author.
To put that figure in perspective, the total number of valid, biological
species of freshwater gastropods inhabiting all U.S. Atlantic drainages, plus
all the drainages of The Ohio, including the Tennessee/Cumberland, summing all
families, including all pulmonate species and all pleurocerid species, as well
as all the hydrobioids, across all or part of 17 eastern U.S. states, amounts
to exactly 107.<div><br /></div><div>For many years, I took it for granted that Bob would be
behind his desk at the USNM, replying to my occasional email requests for
consultation, and to the emails (many greater in their number) I forwarded to
him from others. And then, one day, he
was gone.</div><div><br /></div><div>Bob retired in 2018, the same year I myself would have
retired from the College of Charleston, had all gone according to best-laid
plans <b><span style="color: #783f04;">[16]</span></b>. I tried emailing, and I
tried calling, and nothing. Finally, I
called the front office at the USNM Department of Invertebrate Zoology where I
learned the news. He hadn’t left any
forwarding info.</div><div><br /></div><div>So now, perhaps you, my readership, can dimly see why I led
this blog post with such a potentially-embarrassing anecdote about such a shy
colleague, who is famous in the small world we share for many things, but not
for his sense of humor. <b>Where are you,
Bob?</b> Do you want to set me straight on
any of the slander I have broadcast above?
I have a surprise for you, Old Buddy.</div><div><br /></div><div><br /></div><div><u>Notes</u></div><div>
<p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Hershler, R. (1985) Systematic revision of the
Hydrobiidae (Gastropoda: Rissoacea) of the Cuatro Cienegas Basin, Coahuila,
Mexico.<span style="mso-spacerun: yes;"> </span>Malacologia 26: 31 – 123.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> Davis, G. M. (1979)
The origin and evolution of the Gastropod family Pomatiopsidae, with
emphasis on the Mekong River Triculinae.
Monograph of the Academy of Natural Sciences of Philadelphia 20: 1 –
120.</p><p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Dillon, R.T., Jr. (1984) Geographic distance,
environmental difference, and divergence between isolated populations.
Systematic Zoology 33:69-82. [<a href="https://www.fwgna.org/dillonr/Dillon1984.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> I didn’t apply for the 1986 Smithsonian opening. I had accepted an assistant professorship at
The College of Charleston in 1983, which was a mighty quick turnaround, but
that wouldn’t have stopped me.
Curatorships at the USNM are very, very sweet plums <b><span style="color: #783f04;">[5]</span></b>. What did stop me from applying for the
position at the Smithsonian that Bob Hershler ultimately won in 1986 might be
grist for a future post on the FWGNA blog.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> I happened to notice on a website called federalpay.org
that at his retirement, Bob was earning a base salary of $161,900. That is way more than twice what I ever made,
in 33 years of labor at a mid-sized college of regional reputation, grading thousands of lab reports
written by entitled 19-year-old sorority girls.</p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> <b>Hershler, R. & H-P. Liu (2004)</b> Taxonomic
reappraisal of species assigned to the North American freshwater gastropod
subgenus Natricola (Rissooidea: Hydrobidae). The Veliger 47: 66-81. <b>Hershler, R. & H-P. Liu (2000) </b>A molecular phylogeny of
aquatic gastropods provides a new perspective on biogeographic history of the
Snake River region. Molec. Phyl. Evol. 32: 927-937. For a review of the tempest these two papers stirred up in
the teacup of freshwater gastropod conservation, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Idaho springsnail showdown [<a href="https://fwgna.blogspot.com/2005/04/idaho-springsnail-showdown.html" target="_blank">28Apr05</a>]</li><li>Idaho springsnail panel report [<a href="https://fwgna.blogspot.com/2005/12/idaho-springsnail-panel-report.html" target="_blank">23Dec05</a>]</li><li>When pigs fly in Idaho [<a href="https://fwgna.blogspot.com/2006/01/when-pigs-fly-in-idaho.html" target="_blank">30Jan06</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><span style="color: #783f04;"><b>[7]</b></span> Hershler, R., J.R. Holsinger & L. Hubricht (1990) A
revision of the North American freshwater snail genus <i>Fontigens</i> (Prosobranchia:
Hydrobiidae). Smithsonian Contributions to Zoology 509: 1-49. For an appreciation, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Springsnails of The Blue Ridge [<a href="https://fwgna.blogspot.com/2006/07/springsnails-of-blue-ridge.html" target="_blank">26July06</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> This is a scan of Figure 7 from Hershler, Holsinger
& Hubricht <b><span style="color: #783f04;">[7]</span></b>. It shows camera
lucida outline drawings of penes from ten different populations of <i>F.
nickliniana</i>, collected mostly from Virginia.
Pl = proximal penial lobe, Dl = distal penial lobe, Pf = Penial
filament.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> For appreciations of the work of those two icons of
neoclassical malacology, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The classification of the Lymnaeidae <a href="https://fwgna.blogspot.com/2006/12/classification-of-lymnaeidae.html" target="_blank">[28Dec06</a>]</li><li>Character phase disequilibrium in the <i>Gyraulus</i> of Europe
[<a href="https://fwgna.blogspot.com/2022/02/character-phase-disequilibrium-in.html" target="_blank">4Feb22</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> Hershler, R.
(1994) A review of the North American
freshwater snail genus <i>Pyrgulopsis</i> (Hydrobiidae). Smithsonian Contributions to Zoology 554:
1-115. I mentioned idly “leafing through” this important work back in
2016, for example:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li><i>Marstonia letsoni</i>, quite literally obscure [<a href="https://fwgna.blogspot.com/2016/02/marstonia-letsoni-quite-literally.html" target="_blank">5Feb16</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Hershler & Liu (2017) Annotated Checklist of
Freshwater Truncatelloidean Gastropods of the Western United States, with an
Illustrated Key to the Genera. US Bureau
of Land Management Technical Note 449: 1 – 142.</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> <b>Hershler, R. 1998</b>. A systematic review of the hydrobiid
snails (Gastropoda: Rissooidea) of the Great Basin, western United States. Part
I. Genus <i>Pyrgulopsis</i>. Veliger 41:1-132. <b>Hershler, R. 2001</b>. Systematics of the North and Central
American aquatic snail genus <i>Tryonia</i> (Rissooidea: Hydrobiidae). Smithsonian
Contributions to Zoology 612:1-53. <b>Hershler, R., Frest, T.J. 1996</b>. A review of the North
American freshwater snail genus <i>Fluminicola</i> (Hydrobiidae). Smithsonian
Contributions to Zoology 583:1-41. <b>Hershler, R., Landye, J.J.</b> 1988. Arizona Hydrobiidae.
Smithsonian Contributions to Zoology 459:1-63. <b>Hershler, R., Thompson, F.G.</b> 1992. A review of the aquatic
gastropod subfamily Cochliopinae (Prosobranchia: Hydrobiidae). Malacological
Review Supplement 5:1-140.</p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> Hershler, R., D.B. Madsen, and D.R. Currey (eds) Great
Basin Aquatic Systems History. Smithsonian Contributions to the Earth Sciences
33: 1 – 405 (2002).</p><p class="MsoNormal"><b><span style="color: #783f04;">[14] </span></b>Ironic in light of the title of his 2017 publication,
cited at note <b><span style="color: #783f04;">[11]</span></b> above.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> This is a detail from Figure 2 of Hershler <b><span style="color: #783f04;">[10]</span></b>. It depicts three views of a whole mount penis
dissected from <i>Pyrgulopsis californiensis</i>.
Tg = terminal gland, Pg = penial gland, Vd = ventral gland, Dg = dorsal
glands. </p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> I was banned
from campus and forced into retirement for a Woodrow Wilson quote four weeks
into the spring semester of 2016. A
press release issued by the Provost’s Office at the College of Charleston on
the afternoon of February 21 stated, in part, “We have endured that
sanctimonious asshole for 33 years, 5 months, 21 days, 13 hours and 15 minutes,
and cannot stand him for one second more.”
For a review, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Inside Higher Education [<a href="https://www.insidehighered.com/news/2016/08/08/should-professor-lose-his-job-over-refusing-put-learning-outcome-his-course-syllabus" target="_blank">8Aug16</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal">I used my settlement from the lawsuit to set up the FWGNA as
a sole proprietorship.<o:p></o:p></p></div>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-15024644080227851962022-06-09T10:32:00.007-04:002023-11-27T22:08:57.995-05:00Cytoplasmic Male Sterility in Physa!<p><span style="font-size: xx-small;">Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023c) Cytoplasmic male sterility in Physa! Pp 195 – 206 <b>in</b> The Freshwater Gastropods of North America Volume 7, <i>Collected in Turn One, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC.</span></p><p>Three cheers for our good friend Dr. Patrice David of the
CNRS-CEFE, who together with a team from the Universities of Montpellier and
Lyon, has opened a new window into the mysteries of sex allocation in pulmonate
snails, casting fresh light on mitochondrial evolution across the entire animal
kingdom in the process. Our colleagues
from France have discovered the first case of cytoplasmic male sterility ever
documented outside the vascular plants <b><span style="color: #783f04;">[1]</span></b>.
And they have done so in the most underappreciated experimental model of
our time, the freshwater gastropod <a href="https://www.fwgna.org/species/physidae/p_acuta.html" target="_blank">Physa acuta</a>.</p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidSgjEXRHj5blgI-4elcxu0siSLUFWxbZ0ZWaxYH2UW_v4aLo5kX44rMwgo0lZRddBj6Jmvf-LzyTZnzek7ogCLZJQtWCj8-DAeuwZWcwAB8kXQDx_h5jktiIpAoqJn8X06Ua0A9ghwvYezbn34T_Rx4j4xxP4ehGZChpJ3fThwCQc_zo5hbSwBQ2G7g/s269/maize-sterility.png" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="269" data-original-width="185" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidSgjEXRHj5blgI-4elcxu0siSLUFWxbZ0ZWaxYH2UW_v4aLo5kX44rMwgo0lZRddBj6Jmvf-LzyTZnzek7ogCLZJQtWCj8-DAeuwZWcwAB8kXQDx_h5jktiIpAoqJn8X06Ua0A9ghwvYezbn34T_Rx4j4xxP4ehGZChpJ3fThwCQc_zo5hbSwBQ2G7g/w138-h200/maize-sterility.png" width="138" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Male-fertile & sterile <b><span style="color: #783f04;">[3]</span></b></span></td></tr></tbody></table>Genetic phenomena now understood to result from cytoplasmic
male sterility were reported in plants as early as 1884 <b><span style="color: #783f04;">[2]</span></b>. Many wild
populations of the thistle <i>Cirsium oleraceum</i>, for example, are composed of
mixtures of (normal) monoecious plants producing monoecious offspring and
(male-sterile) female plants producing only female offspring, although always
pollinated from monoecious plants. In a series of papers published between 1916
and 1937, the German geneticist Carl Correns demonstrated that the “female <i>C.
oleraceum</i> plants contained in their cytoplasms some properties which inhibited
the development of male floral parts.”
And in 1939, the obscure Argentinian geneticist E. Gini reported
controlled crosses conclusively demonstrating cytoplasmic male sterility in
certain varieties of maize, which might, however, be modified by a nuclear gene
or genes segregating in the male parent.<p></p>Thistles are ordinary dicots, in the sense that their
flowers bear both stigma and anther, both pollen and ova. Maize is a monocot, and among the just 5% of
all angiosperms with separate male and female inflorescences; the pollen being
produced by the tassel on top, the ovum in the cob below. What unites maize and thistles is that at
least sometimes both demonstrate a mating system called “gynodioecy,” where both hermaphroditic and female
individuals co-exist in a single population.<div><br /><div>Between 1940 and 1970, cytoplasmic male sterility was
discovered in hundreds of species of (at least occasionally) gynodioecious
plants, including many important as crops.
Nuclear genes that moderated the effects of CMS were discovered as
well. In the hands of plant breeders,
CMS became a powerful tool to promote hybridization in normally
self-pollinating varieties of maize, wheat, rice, carrots, onions, and
beets. And as the beet fields blossomed
forth, so too did funding for research into CMS.</div><div><br /></div><div>By the mid-1980s it was clear that CMS was caused by
mitochondrial gene alteration. By the
mid-1990s sterility had been pegged to a variety of genes variably-inserted
into otherwise normal plant mitochondria, encoding proteins that interfered
with pollen formation <b><span style="color: #783f04;">[3]</span></b>. And by the
mid-2000s, the sequence data were rolling in.
It materialized that the plant mitochondrial genome is strikingly
different from animal mtDNA in its evolutionary dynamics: variably sized,
highly repetitive, and characterized by frequent gain, loss, duplication and
rearrangement of genes <b><span style="color: #783f04;">[4]</span></b>.</div><div><br /></div><div>Now, back to France.
You have heard me sing the praises of Dr. Philippe Jarne, his (1993-96)
student Dr. Patrice David, and a bouquet of Montpellier friends and colleagues
in many previous essays posted on this blog.
Most recently we featured their collaboration with a host of researchers
from across the Americas to work out the evolution of the lymnaeid subgenus
<i>Galba</i>, the crappy little amphibious snails serving as intermediate hosts for
the sheep liver fluke Fasciola worldwide <b><span style="color: #783f04;">[5]</span></b>.
Philippe and Patrice also have research interests in <i>Physa</i>, primarily as
a model for the study of sex allocation, extending all the way back to 1995. See note <b><span style="color: #783f04;">[6]</span></b> below for a selection of my
favorite <i>Physa</i> papers published by Philippe, Patrice, and their colleagues over
the years.</div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdZnyynFtAYv4tDg_aQ6VOGHl_RwZonJhgT0KGLYIfS29UT95syXaZq486Mg5FWVDoshigei-VLJRuP3bhQ3qr4npMlt4GuY4Qv1sJEf8qjwU1kjunBsJbecHSDIB9YfztkDeO6_NZmiIgErDr3kJ90B3fN7N6nEFZXNR4Ol815GnZDFj01CkVRO9HAA/s1908/David-etal-graphical-abstract.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1888" data-original-width="1908" height="317" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdZnyynFtAYv4tDg_aQ6VOGHl_RwZonJhgT0KGLYIfS29UT95syXaZq486Mg5FWVDoshigei-VLJRuP3bhQ3qr4npMlt4GuY4Qv1sJEf8qjwU1kjunBsJbecHSDIB9YfztkDeO6_NZmiIgErDr3kJ90B3fN7N6nEFZXNR4Ol815GnZDFj01CkVRO9HAA/s320/David-etal-graphical-abstract.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Graphical abstract from David et al. <b><span style="color: #783f04;">[1]</span></b></span></td></tr></tbody></table><div>That said. A
phenomenon as startling as cytoplasmic male sterility in little brown trash
snails is not something one can design an experiment to discover. Patrice tells me that the breakthrough was
initially made by Dr. Emilien Luquet of the University of Lyon, who has adopted
<i>Physa acuta</i> as a model for the study of phenotypic plasticity. Routinely sequencing the CO1 gene from a
sample of <i>Physa</i> collected in a backwater of the Rhone River east of Lyon, Dr.
Luquet obtained a couple sequences that were, to use the precise, technical
terminology especially developed in Lyon to describe the phenomenon, “weird”
<b><span style="color: #783f04;">[7]</span></b>.</div><div><br /></div><div>Dr. Luquet, together with a team of four colleagues from the
University of Lyon, (Plénet, Lefébure, Konecny and Deglétagne) then developed
and characterized 34 isofemale lines of <i>Physa</i> from the Rhone River backwaters,
29 with normal mitochondrial genotypes and 5 weird. The weird lines bore mitochondria with a
median CO1 sequence divergence more than 20% different from the other members
of their population, or indeed, any of the hundreds of <i>Physa</i> sequences in
GenBank. Sequences of the mitochondrial
16S gene returned the same remarkable result.</div><div><p class="MsoNormal">At this point Dr. Luquet sent samples to our mutual friend
Patrice, saying “I apparently have <i>Physa</i> that came from outer space, look at
them and tell me if this is really <i>Physa acuta</i>.” Patrice, aware that here in North America we
have several species of <i>Physa</i> that are indeed rather cryptic, began a series of
experimental crosses with an albino line of <i>P. acuta</i> developed in the CNRS-CEFE
laboratory.</p><p class="MsoNormal">When mounted by albino controls mating in the male role, the
weird lines of <i>Physa </i>outcrossed readily, and actually showed some evidence of
fecundity improved over the normal lines from Lyon. But it materialized that the weird lines were
male-sterile. They showed much-reduced
behavioral tendency to mount partners in the male role, their seminal vesicles
apparently shrunken, containing very little sperm. They could not self-fertilize. <b> This is the first demonstration of
cytoplasmic male sterility in the animal kingdom</b>…</p><p class="MsoNormal">… but Amy Wethington and I had a shot at it 20 years ago.</p><p class="MsoNormal">Amy and I started working with <i>Physa</i> when she was an
undergraduate student at the College of Charleston in the late 1980s. And our first samples came from a pond in the
state park just around the corner from my house, Charles Towne Landing. That population of <i>Physa</i> became a standard
for 20 papers published over the 20 years that followed <b><span style="color: #783f04;">[8]</span></b>. We called it population C.</p><p class="MsoNormal"><o:p></o:p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcxGCUPdMqGdoNTsJ2TRvTKt6NGfjX3mPxhmzJ2F0u6rNV8J_dc2MfV9rQZlEoIlHbXebaaa2UZMnCtdZ9QC6CsytqWyb4s9RAWgIrnPBv7M5cnGoRpgj0LxBeXOm-bwxOe5NYbl98baoSUTMCCcH7JhUKmsWs6B9XysGMSOVORW6sapMCVnwAV7RsOA/s640/Amy-at-CTL.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="480" data-original-width="640" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcxGCUPdMqGdoNTsJ2TRvTKt6NGfjX3mPxhmzJ2F0u6rNV8J_dc2MfV9rQZlEoIlHbXebaaa2UZMnCtdZ9QC6CsytqWyb4s9RAWgIrnPBv7M5cnGoRpgj0LxBeXOm-bwxOe5NYbl98baoSUTMCCcH7JhUKmsWs6B9XysGMSOVORW6sapMCVnwAV7RsOA/s320/Amy-at-CTL.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Amy at Charles Towne Landing</span></td></tr></tbody></table><p class="MsoNormal">Almost immediately, Amy and I became interested in the
evolutionary relationships between our population C, which we initially
identified as “<i>Physa heterostropha pomilia</i>,” and all the other populations of
trash <i>Physa</i> worldwide, identified with a wide variety of other names. And my readership with admirably long memory
may recall that it was from Philippe Jarne back in 2000 that Amy and I received
the batch of French <i>Physa acuta</i> we used in our experiments demonstrating no
reproductive isolation between population C and five other populations of <i>Physa</i>
that had been known by three different names: <i>Physa acuta</i>, <i>Physa heterostropha</i>,
and <i>Physa integra</i> <b><span style="color: #783f04;">[9]</span></b>.</p><p class="MsoNormal">So given that all six of these populations of <i>Physa</i> from
four states and two European countries were conspecific, Amy and I were next
curious to estimate the amount of genetic divergence among them. A CofC undergraduate named Matt Rhett and I
ran the allozyme gels <b><span style="color: #783f04;">[10]</span></b>, and Amy (now in the PhD program at the University
of Alabama) sequenced two mitochondrial genes (CO1 and 16S) for approximately
20 snails from each of those six populations: C = Charleston, P = Philadelphia, D =
Douglas Lake, Michigan, N = New Harmony, Indiana, F = France, I = Ireland. The gigantic 16s+CO1 neighbor-joining gene
tree that resulted is shown below.</p><p class="MsoNormal">Let’s look at that tree from the bottom up. At the bottom you see two other good
biological species of <i>Physa</i>: three individual <a href="https://www.fwgna.org/species/physidae/p_gyrina.html" target="_blank">Physa gyrina</a>, and three
individual <a href="https://www.fwgna.org/species/physidae/p_pomilia.html" target="_blank">Physa pomilia</a>, which we were calling <i>Physa hendersoni</i> at that time
<b><span style="color: #783f04;">[11]</span></b>. The gigantic middle branch of the
tree shows all six of our <i>Physa acuta </i>populations all mixed up: C, P, D, N, F,
and I, with a little bit of geographic structure but not much. Now what the heck is that branch sticking way
out at the top?</p><p class="MsoNormal">That top branch, labelled C10, C13, C15 and C18, shows four
snails from Charles Town Landing bearing mitochondria with sequences
approximately 30% different from all other <i>Physa acuta</i> from four states and two
European countries. Amy called those
sequences “whacky.”</p><p class="MsoNormal">So in 2004 Amy drafted a manuscript by Wethington, Rhett,
and Dillon to report all our allozyme data and all our sequence data across all
six <i>Physa</i> populations. Meanwhile, I
recruited another undergraduate student, Nick DiNitto, and together Nick and I
went back to the pond at Charles Town Landing, collected 26 adult <i>Physa</i>, and started
isofemale lines. Once the original
mothers had laid eggs, our plan was to enlist the aid of my colleague Bob
Frankis to sequence their CO1 genes, hoping to found pure whacky <b><span style="color: #783f04;">[12]</span></b> cultures
for breeding experiments.</p><p class="MsoNormal"><o:p></o:p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgE0_vxUUmdSlmB3W-Ygg46u6-bNt6umEWxizPcGU-Duc4vIHmp-pdNR6qMnbMBhbBOHkHW0qqcS0jSc-rzTfFJYorF0JN_KWEJptvGjrBTN9QUxZBAQo5qWAn7lgxxqkbJwb6_B6yCEOH7301MynVL5PDfpZt2GcrrA-2Y8SmfBeYAhQ4_AHGOXkW8_A/s702/WRD-04-fig1.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="702" data-original-width="552" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgE0_vxUUmdSlmB3W-Ygg46u6-bNt6umEWxizPcGU-Duc4vIHmp-pdNR6qMnbMBhbBOHkHW0qqcS0jSc-rzTfFJYorF0JN_KWEJptvGjrBTN9QUxZBAQo5qWAn7lgxxqkbJwb6_B6yCEOH7301MynVL5PDfpZt2GcrrA-2Y8SmfBeYAhQ4_AHGOXkW8_A/s320/WRD-04-fig1.jpg" width="252" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">From FWGNA Circular #5 [<a href="https://www.fwgna.org/downloads/FWGNA-Circular-5.pdf" target="_blank">pdf</a>]</span></td></tr></tbody></table><p class="MsoNormal">But alas. Working
with Bob, Nick was able to sequence just six of the original mothers before the
semester came to a close and the project foundered. None of those six bore whacky mitotypes
<b><span style="color: #783f04;">[12]</span></b>. Nick’s poster for the 2004 meeting
of the American Malacological Society in Sanibel, Florida, reporting just N=6 unremarkable CO1 sequences, is available for download from note <b><span style="color: #783f04;">[13]</span></b> below.</p><p class="MsoNormal">Meanwhile Amy was having no success whatsoever interesting
journal editors in publishing the Wethington, Rhett & Dillon manuscript. In the eyes of reviewers, the whacky result
depicted at the top of our Figure 1 invalidated the entire paper. This must be some sort of lab accident! Or cryptic speciation? Either Amy’s technique was hopelessly sloppy,
or our premise was hopelessly wrong. Amy
ultimately gave up trying to publish the separate paper, cut the four whacky
sequences, and folded the rest of the data into her 2004 dissertation<b><span style="color: #783f04;">
[14]</span></b>. Her amazing discovery was
forgotten.</p><p class="MsoNormal">Until today. Today I
am making the original 2004 manuscript of A. R. Wethington, J. M. Rhett and R.
T. Dillon, entitled “Allozyme, 16S, and CO1 sequence divergence among
populations of the cosmopolitan freshwater snail, <i>Physa acuta</i>” available for
download as FWGNA Circular #5, here: </p>
<p class="MsoNormal" style="text-align: center;">- <a href="https://www.fwgna.org/downloads/FWGNA-Circular-5.pdf" target="_blank">Wethington, Rhett & Dillon (2022)</a> -<o:p></o:p></p>
<p class="MsoNormal">And perhaps I should have written “almost forgotten” two
paragraphs above. For in footnote (3) of
my [<a href="https://fwgna.blogspot.com/2016/03/mitochondrial-superheterogeneity-what.html" target="_blank">15Mar16</a>] essay on mitochondrial superheterogeneity, I made passing
reference to “a striking case of mtSH (both COI and 16S) in a Charleston
population of <i>Physa acuta</i>.” Which leads
me to offer two final hypotheses, ask two final questions, and make an appeal.</p><p class="MsoNormal">First hypothesis. It
seems quite likely to me that <b>mtSH = CMS</b> in pulmonate snails broadly. The first report of the phenomenon I
subsequently dubbed “mitochondrial superheterogeneity” came in the 1996 paper
of Thomaz and colleagues, working with the land snail <i>Cepaea nemoralis</i> <b><span style="color: #783f04;">[15]</span></b>. Cases of mtSH have been reported at least
three additional times in the land snails that I know of, and one other time in
a freshwater pulmonate, the limpet <i>Laevapex fuscus</i>. See footnotes (2) and (3) of my [<a href="https://fwgna.blogspot.com/2016/03/mitochondrial-superheterogeneity-what.html" target="_blank">15Mar16</a>]
essay.</p><p class="MsoNormal">Second hypothesis. It seems possible that <b>CMS -> DUI</b> in
bivalves. Doubly-uniparental inheritance
of mitochondria was first reported in the marine mussel <i>Mytilus</i> in the
early-1990s and has subsequently been documented in a wide variety of bivalves,
including the unionid mussels of American freshwaters. As the name implies, researchers have found that
mitochondria can be passed by sperm as well as by egg in these bivalve
groups. And most intriguingly, the
genomes of the male mitochondria and the female mitochondria are always found
to be strikingly divergent. Sophie
Breton of the University of Quebec and a team of bivalve researchers including
our friend Randy Hoeh have just very recently published a nice paper
making this argument in compelling fashion <b><span style="color: #783f04;">[16]</span></b>.</p><p class="MsoNormal">First question. <b>Could
CMS -> MtSH in pleurocerids</b> and other prosobranch snails? That is a stretch I am not intellectually
limber enough to make. Sexes are
separate in the pleurocerids, as in almost all other prosobranch groups,
mechanism of sex determination unknown.
If you wade out into the creek, fish up a nice sample of adult pleurocerids
and crack them open, you will almost always find sex ratios significantly
biased toward the female <b><span style="color: #783f04;">[17]</span></b>. This is a
secondary sex ratio, of course. I don’t
think anybody knows the primary sex ratio for any prosobranch population.</p><p class="MsoNormal">I would love to hypothesize that the mitochondrial
superheterogeneity so often demonstrated by freshwater prosobranch populations
– ten cases listed in footnotes (4), (5), (6), and (7) in my essay of [<a href="https://fwgna.blogspot.com/2016/03/mitochondrial-superheterogeneity-what.html" target="_blank">15Mar16</a>] alone – might be related to such sex ratio biases.
But Whelan & Strong <b><span style="color: #783f04;">[18]</span></b> did not find any relationship between sex
and mt haplotype in their superheterogeneous populations of <i>Leptoxis</i> from
Alabama, and I don’t know where else to look for evidence.</p><p class="MsoNormal">And second question.
<b>What is the origin of CMS</b> in the <i>Physa</i> population of the Rhone
River? Patrice and colleagues ultimately
sequenced the weird mitochondrial genome in its entirety, documenting extreme
divergence everywhere they looked, summing to an eye-popping 44.4% median
deviation from the normal mitotype. Yet
no divergence in the nuclear genome was apparent. Sequencing the (nuclear) 28S gene returned no
significant difference across their entire sample of 34 lines, nor were any
differences in microsatellite gene frequencies apparent. The Mendelian genetics confirm that the Rhone
River at Lyon is inhabited by a single randomly interbreeding population of
<i>Physa acuta</i>.</p><p class="MsoNormal">Which brings us to my appeal. To all of our colleagues who persist in
defining species with mtDNA gene trees, please stop. You’re embarrassing us.</p><p class="MsoNormal">Patrice went on to offer several compelling lines of evidence
suggesting that the weird mitotype results from an acceleration of mutation
rate, perhaps due to some defect in the mitochondrial DNA repair mechanism,
rather than selection on mitochondrial functions more broadly. He further observed that high mutation rates
might both produce male-sterility genes, and help them persist over
evolutionary time, counter to the evolution of nuclear genes restoring male
fertility. There are all sorts of selfish-DNA-type directions one could go from here.</p><p class="MsoNormal">And so, to conclude.
None of the thoughts, questions, hypotheses and speculations outlined above could have flickered through my brain before the
marvelous paper by Patrice David and his colleagues appeared last month. Job well done, all of you!<b> La reussite scientifique de la France est
intimement lie au bonheur de l’Amerique</b> <b><span style="color: #783f04;">[19]</span></b>.</p><p class="MsoNormal"><u><br /></u></p><p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1] </span></b>David, Patrice, Cyril Degletagne, Nathanaëlle Saclier,
Aurel Jennan, Philippe Jarne, Sandrine Plénet, Lara Konecny, Clémentine
François, Laurent Guéguen, Noéline Garcia, Tristan Lefébure, Emilien Luquet
(2022) Extreme mitochondrial DNA divergence underlies genetic conflict over sex
determination. Current Biology 32: 2325-2333. https://doi.org/10.1016/j.cub.2022.04.014.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2]</span></b> The historical review in this paragraph is extracted
from:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>Edwardson, J.R. (1956) Cytoplasmic male-sterility. Botanical Review 22: 696-738.</li><li>Edwardson, J.R. (1970) Cytoplasmic male-sterility. Botanical Review 36: 341 – 420.</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[3]</span></b> Schnable, P.S., and R.P. Wise (1998) The molecular basis of cytoplasmic male
sterility and fertility restoration.
Trends in Plant Science 3: 175 – 180.</p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Galtier, N. (2011) The intriguing evolutionary dynamics
of plant mitochondrial DNA. BMC Biol. 9, 61.
http://www.biomedcentral.com/1741-7007/9/64</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> Alda, Pilar, M. Lounnas, A.Vázquez, R. Ayaqui, M.
Calvopiña, M. Celi-Erazo, R.T. Dillon Jr., L. González Ramírez, E. Loker, J. Muzzio-Aroca, A. Nárvaez, O.
Noya, A. Pereira, L. Robles, R. Rodríguez-Hidalgo, N. Uribe, P. David, P.
Jarne, J-P. Pointier, & S. Hurtrez-Boussès (2021) Systematics and
geographical distribution of <i>Galba</i> species, a group of cryptic and world-wide
freshwater snails. Molecular
Phylogenetics and Evolution 157: 107035. [<a href="https://www.fwgna.org/dillonr/Alda-etal-2021.pdf" target="_blank">pdf</a>] [<a href="https://www.sciencedirect.com/science/article/abs/pii/S1055790320303079?via%3Dihub" target="_blank">html</a>]. For a review, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The American Galba and the French Connection [<a href="https://fwgna.blogspot.com/2021/06/the-american-galba-and-french-connection.html" target="_blank">7June21</a>]</li><li>The American Galba: Sex, Wrecks, and Multiplex [<a href="https://fwgna.blogspot.com/2021/06/the-american-galba-sex-wrecks-multiplex.html" target="_blank">22June21</a>]</li><li>Exactly 3ish American Galba [<a href="https://fwgna.blogspot.com/2021/07/exactly-3ish-american-galba.html" target="_blank">6July21</a>]</li><li>What Lymnaea (Galba) schirazensis is not, might be, and most
certainly is [<a href="https://fwgna.blogspot.com/2021/08/what-lymnaea-galba-schirazensis-is-not.html" target="_blank">3Aug21</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[6] </span></b>Here are a few of my favorite <i>Physa</i> papers from Philippe
and colleagues:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Jarne, P., M-A Perdieu, A-F Pernot, B. Delay, and P. David
(2000)<span style="mso-spacerun: yes;"> </span>The influence of
self-fertilization and grouping on fitness attributes in the freshwater snail
<i>Physa acuta</i>: population and individual inbreeding depression. J. Evol. Biol.
13:645-655.</li><li>Bousset, L., P-Y. Henry, P. Sourrouille, & P. Jarne
(2004)<span style="mso-spacerun: yes;"> </span>Population biology of the
invasive freshwater snail <i>Physa acuta</i> approached through genetic markers,
ecological characterization and demography. Molec. Ecol., 13: 2023-2036.</li><li>Tsitrone A, Jarne P, David P: Delayed selfing and resource
reallocations in relation to mate availability in the freshwater snail <i>Physa
acuta</i>. Amer Natur 2003, 162:474-488.</li><li>Henry PY, Bousset L, Sourrouille P, Jarne P: Partial
selfing, ecological disturbance and reproductive assurance in an invasive
freshwater snail. Heredity 2005, 95:428-436</li><li>Noel, E., Chemtob, Y., Janicke, T., Sarda, V., Pelissie, B.,
Jarne, P., and David, P. (2016). Reduced mate availability leads to evolution
of self-fertilization and purging of inbreeding depression in a hermaphrodite.
Evolution 70, 625–640.</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[7]</span></b> Quoting Patrice, “Initially we called them W for weird;
we later opted for D as in Divergent which sounds more serious and doesn't
induce confusion with W chromosomes.”</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> I have reviewed the many years of fruitful collaboration
that Amy and I enjoyed in quite a few essays previously posted on this
blog. Here are my favorites:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>To identify a Physa, 1989 [<a href="https://fwgna.blogspot.com/2018/10/to-identify-physa-1989.html" target="_blank">3Oct18</a>]</li><li>Albinism and sex allocation in Physa [<a href="https://fwgna.blogspot.com/2018/11/albinism-and-sex-allocation-in-physa.html" target="_blank">5Nov18</a>]</li><li>To identify a Physa, 2000 [<a href="https://fwgna.blogspot.com/2018/12/to-identify-physa-2000.html" target="_blank">6Dec18</a>]</li><li>TRUE CONFESSIONS: I described a new species [<a href="https://fwgna.blogspot.com/2010/04/true-confessions-i-described-new.html" target="_blank">7Apr10</a>]</li><li>What is a Species Tree? [<a href="https://fwgna.blogspot.com/2011/07/what-is-species-tree.html" target="_blank">12July11</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[9] </span></b>Dillon, R. T., A. R. Wethington, J. M. Rhett and T. P.
Smith (2002) Populations of the European freshwater pulmonate <i>Physa acuta</i> are
not reproductively isolated from American <i>Physa heterostropha</i> or <i>Physa
integra</i>. Invertebrate Biology 121:
226-234. [<a href="https://www.fwgna.org/dillonr/Dillon_et_al_2002_InvBiol.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[10]</span></b> I know that an
allozyme survey sounds hopelessly outdated.
A postcard from 1982. But it was
allozyme markers that allowed us to do all our breeding studies. We could not have verified outcrosses without
baseline allozyme surveys such as my students and I labored over for
years. There are a lot of research
groups who wish they had that hopelessly-outdated 1982 technology today.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> Dillon, R. T., J. D. Robinson, and A. R. Wethington
(2007) Empirical estimates of
reproductive isolation among the freshwater pulmonates <i>Physa acuta</i>, <i>P. pomilia</i>,
and <i>P. hendersoni</i>. Malacologia 49: 283 -
292. [<a href="https://www.fwgna.org/dillonr/DillonEtAl07.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> Actually, Nick preferred to call the weird sequences
“zany” rather than “whacky.” So that’s
what we called them on his poster…</p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> DeNitto, N. W., R. C. Frankis and R. T. Dillon (2004)
Extensive mitochondrial CO1 sequence diversity in a population of the
freshwater snail, <i>Physa</i>: Admixture or cryptic speciation? American
Malacological Society, Sanibel Island, FL. [Poster, <a href="https://www.fwgna.org/downloads/denitto-frankis-dillon-2004.pdf" target="_blank">pdf</a>]</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Amy’s dissertation was ultimately published as:
Wethington, A.R., & C. Lydeard (2007) A molecular phylogeny of Physidae
(Gastropoda: Basommatophora) based on mitochondrial DNA sequences. Journal of
Molluscan Studies 73: 241 - 257. [<a href="https://www.fwgna.org/downloads/wethingtonlydeard.pdf" target="_blank">pdf</a>]
For a review, see:</p><p class="MsoNormal"></p><ul style="text-align: left;"><li>The classification of the Physidae [<a href="https://fwgna.blogspot.com/2007/10/classification-of-physidae.html" target="_blank">12Oct07</a>]</li></ul><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[15] </span></b>Thomaz, D., Guiller, A. & Clarke, B. (1996) Extreme
divergence of mitochondrial DNA within species of pulmonate land snails. Proc.
of the Royal Society of London B: Biological Sciences, 263, 363–368.</p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> Breton, Sophie, Donald T. Stewart, Julie Brémaud,
Justin C. Havird, Chase H. Smith, and Walter R. Hoeh (2022) Did doubly uniparental inheritance (DUI) of
mtDNA originate as a cytoplasmic male sterility (CMS) system? Bioessays 44: 2100283.
https://doi.org/10.1002/bies.202100283</p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> Cipiaris, S., W. F. Henley and J.R. Voshell (2012) Population sex ratios of pleurocerid snails
(<i>Leptoxis</i> spp.): Variability and relationships with environmental contaminants
and conditions. Amer. Malac. Bull. 30:
287 - 298.</p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> Whelan, N.V. & E. E. Strong (2016) Morphology, molecules and taxonomy: extreme
incongruence in pleurocerids (Gastropoda, Cerithiodea, Pleuroceridae).
Zoologica Scripta 45: 62 – 87. For a
review, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Mitochondrial superheterogeneity: What we know [<a href="https://fwgna.blogspot.com/2016/03/mitochondrial-superheterogeneity-what.html" target="_blank">15Mar16</a>]</li><li>Mitochondrial superheterogeneity: What it means [<a href="https://fwgna.blogspot.com/2016/04/mitochondrial-superheterogeneity-what.html" target="_blank">6Apr16</a>]</li><li>Mitochondrial superheterogeneity and speciation [<a href="https://fwgna.blogspot.com/2016/05/mitochondrial-superheterogeneity-and.html" target="_blank">3May16</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> The scientific success of France is closely tied to the
good fortune of America. I offer this
benediction as an echo of the Marquis de Lafayette quote with which I ended my
essay of [<a href="https://fwgna.blogspot.com/2021/06/the-american-galba-and-french-connection.html" target="_blank">7June21</a>].</p><p class="MsoNormal"><o:p></o:p></p></div></div>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-2183453736791480712022-05-16T08:10:00.003-04:002022-05-16T14:02:02.282-04:00Freshwater Gastropods of the Tennessee/Cumberland<p>Today we are pleased to announce the expansion of our FWGTN
coverage from its East Tennessee origins though <b>the entirety of the Tennessee
and Cumberland River drainage basins</b>, increasing our sampling area from
approximately 22,000 square miles to over 58,000. We document 54 species of freshwater
gastropods with 16 additional subspecies in this malacologically rich region,
offering ecological and systematic notes for each, as well as detailed
distribution maps, a dichotomous key and a photo gallery. This expanded web resource, coauthored by
R.T. Dillon, M. Kohl and R. Winters, is available here:</p><p style="text-align: center;"><a href="https://www.fwgna.org/FWGTN/" target="_blank"><span style="font-size: medium;">The Tennessee/Cumberland</span></a></p><p>The previous version of our FWGTN website, brought online in
2011 by Dillon & Kohl, covered only the Tennessee River drainage system
from SW Virginia and western North Carolina through East Tennessee to skim the top of North Georgia and stop at the Alabama border. Our 2011 database included 1,674 records from
approximately 767 discrete sites, documenting 39 species and 2 subspecies. The expanded database we release today
includes 4,003 records from approximately 1,700 discrete sites, ranging though
North Alabama and Middle Tennessee to clip the corner of NE Mississippi, plus a
big slice across southern Kentucky as well.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilD6CMs9i006ySeQkPEf1lhAh2Jwq-2OVs8XGnwuL5r4BibdEaLVcGvLttcerhmBxFgnrX5-1-_6p7EA1S2FxepdS42ptizjXILFTdt9faMRd41cI2EUokZE0yu_W7AHTLVZi3Ayl7TSIvlOxRpV66lzRoqKGtB-_lJy5iC2PywINApv0mc3-uzpJpLQ/s5669/Map23-AllSites.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3307" data-original-width="5669" height="187" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilD6CMs9i006ySeQkPEf1lhAh2Jwq-2OVs8XGnwuL5r4BibdEaLVcGvLttcerhmBxFgnrX5-1-_6p7EA1S2FxepdS42ptizjXILFTdt9faMRd41cI2EUokZE0yu_W7AHTLVZi3Ayl7TSIvlOxRpV66lzRoqKGtB-_lJy5iC2PywINApv0mc3-uzpJpLQ/s320/Map23-AllSites.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Click for larger</span></td></tr></tbody></table><p>Among many interesting findings, we report here that three
pleurocerid species previously thought restricted to East Tennessee range
significantly further west: <a href="https://www.fwgna.org/species/pleuroceridae/g_simplex.html" target="_blank">Pleurocera simplex</a> (with its subspecies <a href="https://www.fwgna.org/species/pleuroceridae/g_ebenum.html" target="_blank">ebenum</a>),
<a href="https://www.fwgna.org/species/pleuroceridae/g_arach.html" target="_blank">Pleurocera troostiana</a> (with subspecies <a href="https://www.fwgna.org/species/pleuroceridae/p_troost_perstriata.html" target="_blank">perstriata</a>, <a href="https://www.fwgna.org/species/pleuroceridae/p_troost_edgariana.html" target="_blank">edgariana</a>, and <a href="https://www.fwgna.org/species/pleuroceridae/p_troost_lyonii.html" target="_blank">lyonii</a>) and
Pleurocera clavaeformis (subspecies <a href="https://www.fwgna.org/species/pleuroceridae/p_unciale.html" target="_blank">unciale</a>).
We have also discovered that <a href="https://www.fwgna.org/species/pleuroceridae/g_semisemi.html" target="_blank">Pleurocera semicarinata</a>, previously unknown
further south than Kentucky, ranges through Cumberland drainages well into
Tennessee. The distributions of several
hydrobioid species are also clarified and expanded – more about this in coming
months.</p><p><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNuDYM0Z4k6GEcJ_etaTzKH3aBg9qcIO1aSk6Td0NnEQ5hSWU-v_jQKYKmUYwXjMSZFpm6L1orM3Sm0h-kYS_GgV811EU-Nvb_L2z2tloX__E9o61aZ176fx78CRBatebOk9_HDXovlCYeEyO3Qtb8enyN04xGwp7l5AahsAFLcJpOqHuN3Pby50Xl5w/s682/biogeography-fig2.jpg" style="clear: left; display: inline; float: left; margin-bottom: 1em; margin-right: 1em; text-align: center;"><img border="0" data-original-height="682" data-original-width="624" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNuDYM0Z4k6GEcJ_etaTzKH3aBg9qcIO1aSk6Td0NnEQ5hSWU-v_jQKYKmUYwXjMSZFpm6L1orM3Sm0h-kYS_GgV811EU-Nvb_L2z2tloX__E9o61aZ176fx78CRBatebOk9_HDXovlCYeEyO3Qtb8enyN04xGwp7l5AahsAFLcJpOqHuN3Pby50Xl5w/w183-h200/biogeography-fig2.jpg" width="183" /></a>Our complete FWGNA database, covering the drainages of The
Ohio as well as Atlantic drainages from Georgia to the New York line, now
contains 22,044 records documenting 107 species of freshwater gastropods, with
21 subspecies. We have updated our
overall website with a new continent-scale <a href="https://www.fwgna.org/fwgnabiogeography.html" target="_blank">biogeographic analysis</a>, dividing
records into North Atlantic, South Atlantic, Ohio, and Tennessee/Cumberland
subsets. Our analysis suggests that
natural selection has been more important in the evolution of freshwater pulmonates
than gene flow restriction, but that gene flow restriction has been more
important in the evolution of freshwater prosobranchs than natural selection.</p><p>We also announce today the publication of an updated
“<a href="https://www.fwgna.org/fwgnasynthesis.html" target="_blank">Synthesis v3.1</a>,” ordering our 107 species by their incidence in our
continental database and assigning fresh FWGNA incidence ranks to all.</p><p>So, visit the FWGNA web resource again, for the first time!</p><p class="MsoNormal"><o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0tag:blogger.com,1999:blog-1925453458905823877.post-63024828012444309742022-04-05T11:53:00.008-04:002023-11-22T17:33:32.218-05:00The ham, the cheese, and Lithasia jayana<p><span style="font-size: xx-small;">Editor’s Notes – This is the fifth and final installment of my series
on the population genetics and systematic relationships of the Duck River
<i>Lithasia</i>. If you are interested in the
science, you probably ought to review my posts of <a href="https://fwgna.blogspot.com/2021/12/intrapopulation-gene-flow-lithasia.html" target="_blank">7Dec21</a>, <a href="https://fwgna.blogspot.com/2022/01/what-is-character-phase-disequilibrium.html" target="_blank">4Jan22</a>, <a href="https://fwgna.blogspot.com/2022/03/the-third-most-amazing-research-results.html" target="_blank">3Mar22</a>, and <a href="https://fwgna.blogspot.com/2022/03/no-reproductive-isolation-between.html" target="_blank">28Mar22</a>
before proceeding. Or you could simply
enjoy this essay for what it is, a true tale from the wild west days of American
malacology. </span></p><p><span style="font-family: times; font-size: x-small;">This essay was ultimately published as: Dillon, R.T., Jr. (2023b) The ham, the cheese, and Lithasia jayana. Pp 183 – 192 </span><b style="font-family: times; font-size: x-small;">in</b><span style="font-family: times; font-size: x-small;"> The Freshwater Gastropods of North America Volume 6, </span><i style="font-family: times; font-size: x-small;">Yankees at The Gap, and Other Essays</i><span style="font-family: times; font-size: x-small;">. </span><a href="https://www.fwgna.org/publications/index.html" style="font-family: times; font-size: x-small;" target="_blank">FWGNA Project</a><span style="font-family: times; font-size: x-small;">, Charleston, SC </span></p><p>“Well, Ahlstedt, is this <i>jayana</i> or is it not?” That was the punchline of a story told me by
my major advisor, Dr. George Davis, shortly after I arrived at the Philadelphia
Academy of Natural Sciences in the summer of 1977. Why was that question so weighty? And why have I remembered the saga from which
it springs over 40 years now, to pass it along to future generations of
malacologists?</p><p>Previously, on the FWGNA blog! In December and January, we obsessed at great
length over <i>Lithasia geniculata</i>, with its three subspecies, extending down the
275 mile length of the Duck River of Middle Tennessee, bearing smooth, oblong
shells in the headwaters, developing robust, bumpy shoulders in the lower
reaches. In his seminal (1940) monograph <b><span style="color: #783f04;">[1]</span></b>, Calvin Goodrich also identified a
second species of <i>Lithasia</i> in the Duck, bearing a more acute apex and angled
(sometimes even tuberculate) shell, extending only from about river mile 186 to
the mouth. These he identified as
<i>Lithasia duttoniana</i>.</p><p>This month’s episode begins in Washington, as a whispered exchange in the
hallowed halls of Congress. In 1969, just
before the dawn of the environmental movement, federal funding was secured for
the construction of two new dams on the Duck River: the smallish Normandy Dam
at RM 248, and a larger and more expensive Columbia Dam, downstream around RM
145. The Normandy Dam was completed in
1976.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyDinHKaBCeXW26wCH7BTIj9zrB9SxGbn-fYq5zBRqL1zPrhHMnLE3Rh__578k4wMbTkYw6Cf5lXPC_PZUyhCgZlwDLxqNBSk19BPegiI3Kzw_oS4rtAepqt3TBuUlcDeJYTgxSxoPa45ivqM5LAVQqJPEUGGvuT1-_LpbNlCBTEbs8bmQJxMPUM2W4w/s1024/normandy-dam.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="768" data-original-width="1024" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyDinHKaBCeXW26wCH7BTIj9zrB9SxGbn-fYq5zBRqL1zPrhHMnLE3Rh__578k4wMbTkYw6Cf5lXPC_PZUyhCgZlwDLxqNBSk19BPegiI3Kzw_oS4rtAepqt3TBuUlcDeJYTgxSxoPa45ivqM5LAVQqJPEUGGvuT1-_LpbNlCBTEbs8bmQJxMPUM2W4w/s320/normandy-dam.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Normandy Dam (TVA)</span></td></tr></tbody></table><p>But the National Environmental Policy Act went into effect
January 1, 1970, the Clean Water Act in 1972, the and the Endangered Species
Act in 1973. The TVA found itself
required to file an environmental impact statement for the Columbia Dam, even
as its construction proceeded apace. And Dr.
George M. Davis, fresh out of the Army and sitting in the Pilsbry Chair of
Malacology at the ANSP, was awarded a contract to survey the Duck for
potentially endangered pleurocerid snails.</p><p>George Davis’ pleurocerid taxonomy was idiosyncratic. He began by noticing that in almost all
aspects of their biology, including body size, life habit, and shell
morphology, pleurocerid populations of the Haldeman's 1840 genus <i>Lithasia</i> are
not strikingly different from Lea's monotypic genus <i>Io </i>of 1831. Davis therefore synonymized <i>Lithasia</i> under<i> Io</i>
and recognized five taxa in the Duck River: <i>Io geniculata geniculata</i>, <i>Io
geniculata pinguis</i>, <i>Io salebrosa</i>, <i>Io armigera duttoniana</i> and <i>Io armigera jayana</i>. The identities of Davis’ <i>Io geniculata
geniculata</i>, <i>Io geniculata pinguis</i>, and<i> Io armigera duttoniana</i> will by now be
obvious to my readership. “<i>Io salebrosa</i>”
was Davis’ name for what Goodrich would have called <i>Lithasia geniculata
fuliginosa</i>. What was “<i>Io armigera
jayana</i>?”</p><p>The idea that a pleurocerid population matching Isaac Lea’s
nomen “<i>jayana</i>” in the Duck River was especially controversial when Davis filed
his report in 1974 <b><span style="color: #783f04;">[2]</span></b>. Isaac Lea <b><span style="color: #783f04;">[3]</span></b> published its brief, Latinate description in July <b><span style="color: #783f04;">[4]</span></b> of 1841: “Hab.
Cany Fork, DeKalb Co., Tenn. – Dr. Troost <b><span style="color: #783f04;">[5]</span></b>.”
In his more complete English description of 1846, Lea emphasized “It
very closely resembles the <i>M. armigera</i> (Say), in most of its characters, but
may at once be distinguished by the double row of tubercles, the <i>armigera</i> never
possessing distinctly more than one row <b><span style="color: #783f04;">[6]</span></b>.”</p><p>Lea’s selection of Mr. Say’s <i>Melania armigera</i> as a point of
comparison is especially significant.
Described by Thomas Say in 1821 from “The Ohio River” <b><span style="color: #783f04;">[7]</span></b>, the range of populations
today identified as <i>Lithasia armigera</i> extends through much of the lower
Cumberland and Tennessee Rivers as well <b><span style="color: #783f04;">[1]</span></b>, including the Tennessee at the
mouth of the Duck. And the resemblance
between Mr. Lea’s <i>jayana</i> and Mr. Say’s <i>armigera</i> is indeed close, as shown in
the montage of Tryon’s <b><span style="color: #783f04;">[8]</span></b> figures below.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjt2MzMIzALNPDOOqZPnXFDrtd09D047-vY63489OJI24JgmRnwv9zpBy50PjWiyPAMF1oLMJuzYA6wOqjc8XX1Ox20yQeO-4LDAnIkRnypnSzhND2_tgQQ75wSg72UCQD39cTAIrZF9zmuZkuyKmawhO_0482k2HAVsrtyqpfusHeYL_a9GYr5pcIyA/s640/armigera&jayana-tryon.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="312" data-original-width="640" height="156" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjt2MzMIzALNPDOOqZPnXFDrtd09D047-vY63489OJI24JgmRnwv9zpBy50PjWiyPAMF1oLMJuzYA6wOqjc8XX1Ox20yQeO-4LDAnIkRnypnSzhND2_tgQQ75wSg72UCQD39cTAIrZF9zmuZkuyKmawhO_0482k2HAVsrtyqpfusHeYL_a9GYr5pcIyA/s320/armigera&jayana-tryon.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Two <i>L. armigera</i> left, two <i>L.</i> <i>jayana</i> right <b><span style="color: #783f04;">[8]</span></b></span></td></tr></tbody></table>Goodrich recognized neither<i> armigera</i> nor <i>jayana</i> in the Duck
River. Goodrich identified all the
<i>Lithasia</i> bearing acutely-spired shells with tubercles or spines inhabiting the
Duck River as<i> L. duttoniana</i>, a species Lea described in brief Latinate form
about five months prior <b><span style="color: #783f04;">[4] </span></b>to his description of <i>M. jayana</i>: “Hab. Waters of
Tennessee, Dr. Troost. Duck River, Maury
Co. Tenn., Mr. Dutton <b><span style="color: #783f04;">[9]</span></b>.” Lea never
compared his <i>M. duttoniana</i> to any other species of what we would identify today
as a <i>Lithasia: armigera, jayana</i> or anything else.<div><br /></div><div>The only population of <i>L. jayana</i> that Goodrich recognized in
his 1940 monograph was the Caney Fork type population, and that population seems
to have been extincted by the closing of the Center Hill Lake dam and
associated development in 1948. So if
Davis’ Duck River record of “<i>Io armigera jayana</i>” was to be believed, the last
remaining population of a genuinely endangered species would be smack in the
middle of the Duck River where the Columbia Dam was even at that time being
constructed.</div><div><p class="MsoNormal">The scene now shifts to the sleepy little East Tennessee
company town of Norris, were in 1974 the TVA hired a promising young biologist
named Steven A. Ahlstedt to work in its Department of Forestry, Fisheries, and
Wildlife Development <b><span style="color: #783f04;">[10]</span></b>. Steve is an
excellent scientist, with superb field skills and a great eye for freshwater
mollusks. He had a reprint of Tryon’s
monograph on his shelf, and all of Goodrich’s papers in the top drawer of his filing cabinet, but very
little of Goodrich’s work is illustrated, and to match Goodrich with Tryon is a
bitch. And this was six years before the
EPA published The Gospel According To Jack Burch <b><span style="color: #783f04;">[11]</span></b>. So the TVA sent Steve to the University of Michigan
Museum of Zoology to learn freshwater malacology hands-on.</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">And the stage is now set.
In the fall of 1975 the telephone rang on George Davis’ desk at the
Academy of Natural Sciences in Philadelphia.
It was the receptionist downstairs.
She reported that a team of TVA biologists had presented themselves at
the front door and were requesting admission to the Malacology Department to
examine his Duck River pleurocerid collections.
They had no appointment.</p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpBcAUpq2GqUkblBzUcyGmHA7pcV6rOeTvLu3uAXtYHPosvkxSV3Vf2847lxEz91ajppijIrz7GNVRpagWuCIDlozRYXtexxa6iqvrekDMmCShHBuM5xcWCdwVd-9sUBGBQzmkaKwkgY6s9t4-sm1z2RvLNCZ44iVyNC2NXeCvhirlKjQAvoDTLHR0vw/s491/duttoniana-tryon.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" data-original-height="491" data-original-width="480" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpBcAUpq2GqUkblBzUcyGmHA7pcV6rOeTvLu3uAXtYHPosvkxSV3Vf2847lxEz91ajppijIrz7GNVRpagWuCIDlozRYXtexxa6iqvrekDMmCShHBuM5xcWCdwVd-9sUBGBQzmkaKwkgY6s9t4-sm1z2RvLNCZ44iVyNC2NXeCvhirlKjQAvoDTLHR0vw/w196-h200/duttoniana-tryon.jpg" width="196" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Two<i> L. duttoniana</i> <b><span style="color: #783f04;">[8]</span></b></span></td></tr></tbody></table><p></p><p class="MsoNormal">The members of the TVA team were John Bates, Billy Isom,
Steve Ahlstedt and Donelly Hill. Bates
was, at that time, a professor at Eastern Michigan University and Research
Associate at the UMMZ <b><span style="color: #783f04;">[12]</span></b>. Isom worked
for the TVA at their Muscle Shoals office <b><span style="color: #783f04;">[13]</span></b>.
Hill was a supervisor, with a fisheries background.</p><p class="MsoNormal">Like my Momma used to say, “You could have called.” George Davis was still livid about the
surprise nature of this audit when he told me the story two years later. The TVA team asserted that they had a right
to examine the Duck River collections, since the agency they represented had
paid for them. Davis countered that he
would need reimbursement for the time required by his curatorial staff to pull
the lots. The TVA team went away
threatening to get a court order but returned the next day with a purchase
order instead.</p><p class="MsoNormal">Davis would not admit either Bates or Isom into the
collection. They were notorious guns-for-hire
in the wild west era of American freshwater malacology, and Davis did not trust
them. Neither did Steve Ahlstedt, for
that matter. So, in the end, Donelly
Hill sent the most junior member of the team, alone, up the elevator into the ANSP
malacology collection to face the Wrath of George. Steve tells me that he felt like he was “caught
between the ham and the cheese.”</p><p class="MsoNormal">At high noon the fateful shot rang out over Benjamin
Franklin Parkway, “Well, Ahlstedt, is this <i>jayana</i> or is it not?” And Steve’s reply was … (dramatic pause)…
affirmative.</p><p class="MsoNormal">The lower reaches of the Duck River, from about RM 60 to the
mouth, are indeed inhabited by a population of <i>Lithasia</i> bearing shells
indistinguishable from type collections made of <i>L. jayana</i> in the Caney Fork. And since Isaac Lea and his contemporaries
defined gastropod species by shell morphology alone, and since the Duck shells in
George Davis’ right hand matched the Caney Fork types, they were, by
definition, <i>Lithasia jayana</i>.</p><p class="MsoNormal">So, Davis’ pleurocerid identifications stood. And in 1984, after a
ten-year period of comment, revision and study, his taxa were included in a
gigantic laundry-list of candidate invertebrates offered for review by the
USFWS as <i>Lithasia jayana</i>, <i>L. duttoniana</i>, <i>L. geniculata</i>, <i>L. pinguis</i>, and <i>L.
salebrosa</i> <b><span style="color: #783f04;">[15]</span></b>. Nothing ever came of that proposal, however, and <i>Lithasia
jayana</i> receded back into sincere obscurity, as opposed to the mere obscurity it
had enjoyed in the 1970s.</p><p class="MsoNormal"><o:p></o:p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2Bb98u4HxZT4x1y6pYEpGlJ2NKMMULE4ieBUuREOWzTtHiFbeA0Pj_x_ZqcdMtNz1PpiuUDMw87ItkbqOu5dikwavQSlhz9ixOKG1xpAE3UsAX0notx2B_6ztvP0hUVpSOu5Kn9h86diMSyRJLPhbAnGGsk6uS6SAEYT9zDab5OnN9Dlt8kqIqOHKzw/s3863/columbia-dam.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="3863" data-original-width="3475" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2Bb98u4HxZT4x1y6pYEpGlJ2NKMMULE4ieBUuREOWzTtHiFbeA0Pj_x_ZqcdMtNz1PpiuUDMw87ItkbqOu5dikwavQSlhz9ixOKG1xpAE3UsAX0notx2B_6ztvP0hUVpSOu5Kn9h86diMSyRJLPhbAnGGsk6uS6SAEYT9zDab5OnN9Dlt8kqIqOHKzw/s320/columbia-dam.jpg" width="288" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">The abandoned Columbia Dam, 1986 [14]</span></td></tr></tbody></table><p class="MsoNormal">But it did not matter.
By that point, Steve Ahlstedt and his colleagues had documented populations
of genuinely-endangered unionids in the Duck – species that had already been entered
into the Federal list, as early as 1977.
Construction was halted on the 90% complete Columbia Dam in 1983, never
to resume. According to Steve, “They
left their coffee cups on their desks.” The $83M project was demolished in 1999,
and the 12,800 acres it was planned to inundate turned over to the state
wildlife resources agency.</p><p class="MsoNormal">But although the name of <i>Lithasia jayana</i> disappeared from
the public eye, it remained printed in the pages of dusty tomes, and scrawled on
the labels of moldering museum collections.
And in 2003 our colleagues Russ Minton
& Chuck Lydeard pulled it back from sincere obscurity into mere obscurity once
again in the paper we reviewed early last month <b><span style="color: #783f04;">[16]</span></b>. Russ and Chuck reported no mtDNA sequence divergence between
the robust, doubly-spined populations that Davis identified as <i>jayana</i> and more
lightly shelled populations, tuberculate at best, that Davis (and everybody
else prior to 2003) identified as <i>Lithasia duttoniana</i>.</p><p class="MsoNormal">Nor is there any allozyme difference between <i>jayana</i> and
<i>duttoniana</i>. Late last month I posted an
unusually technical report on this blog, which I did not advertise at the time,
so most of you probably missed it. If
you’re serious about the science, you might want to open this link in a new
window [<a href="https://fwgna.blogspot.com/2022/03/no-reproductive-isolation-between.html" target="_blank">28Mar22</a>]. Or you could just
scroll down directly below the present post, skim that essay and scroll
back. Or you could just believe the
paragraph that follows.</p><p class="MsoNormal">When Paul Johnson sent me all those <i>Lithasia</i> samples from
the Duck River back in the summer of 2002, there were three bags from Site E
and three bags from Site F – one labelled <i>L. geniculata geniculata </i>(which we
talked about in December, January, and early March), one labelled <i>L. duttoniana</i>
(which we talked about in January, early March, and late March) and one
labelled <i>L. jayana</i>. Using gene
frequencies at three allozyme-encoding loci, I was indeed able to distinguish <i>L.
geniculata</i> from <i>L. duttoniana</i>. But there
is no genetic distinction whatsoever between <i>L. duttoniana</i> and <i>L. jayana</i>. They seem to be simple shell forms of the
same biological species.</p><p class="MsoNormal">So now the time has come to sum up, over all five essays in
this extended series. The Duck River is
inhabited by two biological species of large-bodied pleurocerid snails
referable to the genus <i>Lithasia</i>. One of
those species bears smooth, high-spired, shells in the headwaters, becoming more
robust, oblong and bumpy downstream and out into the main Tennessee River. The modern era of American malacology was
born in 1934, when Calvin Goodrich realized that populations bearing all those
smooth-to-bumpy shells are conspecific, lowering the specific nomina assigned
to two upstream forms, <i>pinguis</i> and <i>fuliginosa</i>, to subspecific status under the
downstream nomen <i>Lithasia geniculata</i>.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsBq6Z4gwrswNHG8m4lI-vC4UhuUbgEddP8ugqrUOTpgw5PuCbLhLRxOZZLhuNsV4TnlcY_sHUu5JSZx2R_N7FIc-Yq_j4dVEz2ZJtFqmi1LJqrmYMnZQLN3Ny71hZ-undk5Nn40kllhIBdK-1LZ5qOmVx6slpgCrVmOHOzhbPlFDv_h1y3iyWizY3YQ/s640/bob-winters-necklace-label.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="640" data-original-width="494" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhsBq6Z4gwrswNHG8m4lI-vC4UhuUbgEddP8ugqrUOTpgw5PuCbLhLRxOZZLhuNsV4TnlcY_sHUu5JSZx2R_N7FIc-Yq_j4dVEz2ZJtFqmi1LJqrmYMnZQLN3Ny71hZ-undk5Nn40kllhIBdK-1LZ5qOmVx6slpgCrVmOHOzhbPlFDv_h1y3iyWizY3YQ/s320/bob-winters-necklace-label.jpg" width="247" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Gastropod magafauna of Caney Fork, 500 A.D. <b><span style="color: #783f04;">[17]</span></b></span></td></tr></tbody></table><p class="MsoNormal">Living together with <i>Lithasia geniculata</i> in the lower
reaches of the Duck River is a second species of <i>Lithasia</i>, genetically quite similar
to <i>L. geniculata</i>, but morphologically distinct and reproductively
isolated. These snails also demonstrate
a cline in shell morphology, from a single row of light tubercules upstream,
becoming more robust and heavily (even doubly) spined downstream, out into the
main Tennessee River. Then by analogy
with <i>L. geniculata</i>, let us <b>lower the specific nomina assigned to the two
upstream forms, <i>duttoniana</i> and <i>jayana</i>, to subspecific status under the
downstream nomen <i>Lithasia armigera</i></b>.</p><p class="MsoNormal">This hypothesis is supported by the genetic data, both by the
<i>duttoniana/jayana</i> allozyme results offered late last month [<a href="https://fwgna.blogspot.com/2022/03/no-reproductive-isolation-between.html" target="_blank">28Mar22</a>], and by the
<i>L. armigera</i> CO1 sequences published by Minton & Lydeard, reviewed early last
month [<a href="https://fwgna.blogspot.com/2022/03/the-third-most-amazing-research-results.html" target="_blank">3Mar22</a>]. It was originally
suggested on the basis of shell morphology by Calvin Goodrich himself, way back
in 1921 <b><span style="color: #783f04;">[18]</span></b>, although by 1940, he had apparently changed his mind <b><span style="color: #783f04;">[1]</span></b>. It was also advocated by Davis in 1974 <b><span style="color: #783f04;">[2]</span></b>.</p><p class="MsoNormal">So this morning I have uploaded three fresh pages to the
FWGNA website: <i><a href="https://www.fwgna.org/species/pleuroceridae/l_armigera_duttoniana.html" target="_blank">Lithasia armigera duttoniana</a></i>, <i><a href="https://www.fwgna.org/species/pleuroceridae/L_armigera_jayana.html" target="_blank">L. armigera jayana</a></i>, and <i><a href="https://www.fwgna.org/species/pleuroceridae/l_armigera.html" target="_blank">L.armigera armigera</a></i>. And I remind my
readership that the FWGNA defines the word “subspecies” to mean “populations of
the same species in different geographic locations, with one or more
distinguishing traits.” This is the
definition of the term as developed by the architects of the Modern Synthesis,
and means precisely what it says, neither more nor less <b><span style="color: #783f04;">[19]</span></b>.</p><p class="MsoNormal">There need be no additively-genetic basis for the
“distinguishing traits.” Indeed, in the
genus <i>Pleurocera</i>, a very closely analogous trend from gracile shells in the
headwaters to robust shells in the big rivers has been convincingly attributed
to cryptic phenotypic plasticity <b><span style="color: #783f04;">[20]</span></b>. The heritable component of the shell
morphological variance among populations identifiable as <i>jayana</i>, <i>duttoniana</i>,
and <i>armigera</i> (s.s.) remains an open question.</p><p class="MsoNormal"><br /></p>
<p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Goodrich, C. 1940. The Pleuroceridae of the Ohio River
drainage system. Occasional Papers of the Museum of Zoology, University of
Michigan 417:1 - 21.</p><p class="MsoNormal"><b><span style="color: #783f04;">[2] </span></b>Davis, G.M. 1974.
Report on the rare and endangered status of a selected number of
freshwater Gastropoda from southeastern U.S.A. U.S. Fish & Wildlife
Service. Washington, DC. 51 p.</p><p class="MsoNormal"><span style="color: #783f04;"><b>[3]</b></span> For more about “The Nestor of American Naturalists” see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Isaac Lea Drives Me Nuts [<a href="https://fwgna.blogspot.com/2019/11/isaac-lea-drives-me-nuts.html" target="_blank">5Nov19</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[4]</span></b> Lea, I (1841) Proceedings of the American Philosophical
Society 2 (19): 83. There has
historically been much controversy regarding the exact publication dates for Lea’s
descriptions. The date on the cover of
PAPS 2(19) is “July – October 1841,” a four month window. Lea’s description of <i>jayana</i> appears in the
“Stated Meeting of July 16,” prefaced by a statement that the paper itself was
“read on the 18<sup>th</sup> of June last.”
That’s as far down the rabbit hole as I care to go.</p><p class="MsoNormal"><b><span style="color: #783f04;">[5]</span></b> For a brief biography of Gerard Troost, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>On the Trail of Professor Troost [<a href="https://fwgna.blogspot.com/2019/12/on-trail-of-professor-troost.html" target="_blank">6Dec19</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[6]</span></b> Lea, I (1846) Continuation of Mr. Lea’s paper on fresh
water and land shells. Transactions of
the American Philosophical Society 9(1) 1 – 31.</p><p class="MsoNormal"><b><span style="color: #783f04;">[7] </span></b>Say, T. (1821) Journal of the Academy of Natural
Sciences of Philadelphia (First Series) 2: 178.</p><p class="MsoNormal"><b><span style="color: #783f04;">[8]</span></b> Tryon, G. W. (1873)
Land and Freshwater shells of North America Part IV, Strepomatidae. Smithsonian Miscellaneous Collections 253: 1
- 435.</p><p class="MsoNormal"><b><span style="color: #783f04;">[9]</span></b> Lea, I. (1841) Proceedings of the American Philosophical
Society Volume 2(16) 15.</p><p class="MsoNormal"><b><span style="color: #783f04;">[10] </span></b>I met Steve in 1975, the summer after my
sophomore year at Virginia Tech, when I was blessed to be offered an hourly job
with the TVA in Norris. Malacological posterity will owe him a debt of gratitude for sharing his recollections of the events recorded here.</p><p class="MsoNormal"><b><span style="color: #783f04;">[11]</span></b> This is a difficult work to cite. J. B. Burch's <i>North American Freshwater
Snails</i> was published in three different ways.
It was initially commissioned as an identification manual by the US EPA
and published by the agency in 1982. It
was also serially published in the journal Walkerana (1980, 1982, 1988) and
finally as stand-alone volume in 1989 (Malacological Publications, Hamburg,
MI).</p><p class="MsoNormal"><b><span style="color: #783f04;">[12]</span></b> John Morton Bates (b. 1932) began his career at the
ANSP 1956 – 1966, then accepted a tenured position at Eastern Michigan
University, with a research associate appointment at the UMMZ. He left Michigan to found “Ecological
Consultants” of Shawsville, VA, with Sally Dennis. I’m not sure what became of him after that.</p><p class="MsoNormal"><b><span style="color: #783f04;">[13]</span></b> Billy G. Isom (b. 1932) was an ecologist for the
Tennessee Stream Pollution Control Board 1957 – 1963 before joining the TVA as
a supervisor in the Limnology Section at Muscle Shoals, AL. I think he is still alive and living in
Killen, AL at the age of 89.</p><p class="MsoNormal"><b><span style="color: #783f04;">[14]</span></b> Tennessee Valley Authority (1999) Use of Lands Acquired
for the Columbia Dam Component of the Duck River Project. Final Environmental
Impact Statement.</p><p class="MsoNormal"><b><span style="color: #783f04;">[15]</span></b> Federal Register FR-1984-05-22. Endangered and
threatened wildlife and plants; Review of invertebrate wildlife for listing as
endangered or threatened species.
49(100) 21664 – 21675.</p><p class="MsoNormal"><b><span style="color: #783f04;">[16]</span></b> Minton, R. L. and C. Lydeard. 2003. Phylogeny,
taxonomy, genetics, and global heritage ranks of an imperiled, freshwater snail
genus <i>Lithasia </i>(Pleuroceridae). Molecular Ecology 12:75-87. For my review, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>The third-most amazing research results ever published for
the genetics of a freshwater gastropod population. And the fourth-most amazing,
too. [<a href="https://fwgna.blogspot.com/2022/03/the-third-most-amazing-research-results.html" target="_blank">3Mar22</a>]</li></ul><p></p><p class="MsoNormal"><b><span style="color: #783f04;">[17]</span></b> This necklace was discovered by Cousin Bob Winters in a
rock shelter on the north shore of Center Hill Reservoir, DeKalb County, TN.</p><p class="MsoNormal"><b><span style="color: #783f04;">[18]</span></b> Goodrich, C. (1921)
Something about <i>Angitrema</i>. The
Nautilus 35: 58 – 59.</p><p class="MsoNormal"><b><span style="color: #783f04;">[19]</span></b> If the clean, clear definition of the word “subspecies”
confuses you, read:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>What is a subspecies? [<a href="https://fwgna.blogspot.com/2014/02/what-is-subspecies.html" target="_blank">4Feb14</a>]</li><li>What subspecies are not [<a href="https://fwgna.blogspot.com/2014/03/what-subspecies-are-not.html" target="_blank">5Mar14</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><b><span style="color: #783f04;">[20]</span></b> Cryptic phenotypic plasticity is defined as “intrapopulation
morphological variation so extreme as to prompt an (erroneous) hypothesis of
speciation.” For examples, see:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><ul style="text-align: left;"><li>Goodrichian Taxon Shift [<a href="https://fwgna.blogspot.com/2007/02/goodrichian-taxon-shift.html" target="_blank">20Feb07</a>]</li><li>Goodbye Goniobasis, Farewell Elimia [<a href="https://fwgna.blogspot.com/2011/03/goodbye-goniobasis-farewell-elimia.html" target="_blank">23Mar11</a>]</li><li>Pleurocera acuta is Pleurocera canaliculata [<a href="https://fwgna.blogspot.com/2013/06/pleurocera-acuta-is-pleurocera.html" target="_blank">3June13</a>]</li><li>Elimia livescens and Lithasia obovata are Pleurocera semicarinata [<a href="https://fwgna.blogspot.com/2014/07/elimia-livescens-and-lithasia-obovata.html" target="_blank">11July14</a>]</li></ul><o:p></o:p><p></p>
<p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><o:p></o:p></p></div>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com2tag:blogger.com,1999:blog-1925453458905823877.post-90632265145201711832022-03-28T09:24:00.004-04:002023-11-22T16:45:20.234-05:00No reproductive isolation between Lithasia populations of the duttoniana and jayana forms in the Duck River, Tennessee<p><span style="font-family: times; font-size: xx-small;">Editor’s Notes - We have always tried to avoid excessively technical posts on the FWGNA blog. I typically publish formal research results
elsewhere first and subsequently refer to those results here in a more casual
tone. Two of the three essays I have
posted in recent months about the <i>Lithasia</i> of the Duck River [<a href="https://fwgna.blogspot.com/2021/12/intrapopulation-gene-flow-lithasia.html" target="_blank">7Dec21</a>] and
[<a href="https://fwgna.blogspot.com/2022/01/what-is-character-phase-disequilibrium.html" target="_blank">4Jan22</a>] were, for example, preceded by brief, technical notes published in
<i>Ellipsaria</i> (the newsletter of the Freshwater Mollusk Conservation Society) in
2020.</span></p><p><span style="font-family: times; font-size: xx-small;">The post that follows, however, is technical. Its publication was suppressed by FMCS Newsletter
editor Dr. John Jenkinson because one of our mutual colleagues on the FMCS
Board <b><span style="color: #783f04;">[1]</span></b> called to Dr. Jenkinson’s attention that <i>Ellipsaria</i> content
is being indexed by Google Scholar, and hence that the hypotheses I have
proposed below <b><span style="color: #783f04;">[2]</span></b> might fall upon naïve and uncritical eyes. This essay was ultimately published as: Dillon, R.T., Jr. (2023b) No reproductive isolation between Lithasia populations of the duttoniana and jayana forms in the Duck River, Tennessee. Pp 175 – 182 <b>in</b> The Freshwater Gastropods of
North America Volume 6, <i>Yankees at The Gap, and Other Essays</i>. <a href="https://www.fwgna.org/publications/index.html" target="_blank">FWGNA Project</a>, Charleston, SC </span></p><p>The taxonomic history of the pleurocerid genus <i>Lithasia</i>
(Haldeman 1840) is a long and complicated one.
Goodrich (1940) recognized 16 taxa of <i>Lithasia</i> with smooth shells, 3
with tuberculate shells, and 5 taxa bearing shells with spines or acute
protuberances. This last category
comprised<a href="https://www.fwgna.org/species/pleuroceridae/l_armigera_duttoniana.html" target="_blank"> <i>Lithasia duttoniana</i></a>, described by Lea (1841) from the Duck River, <i><a href="https://www.fwgna.org/species/pleuroceridae/L_armigera_jayana.html" target="_blank">L. jayana</a></i>, also described by Lea (1841) from Caney Fork (of the Cumberland), and
three subspecies of <i><a href="https://www.fwgna.org/species/pleuroceridae/l_armigera.html" target="_blank">L. armigera</a></i>, described by Say (1821) from the Ohio River.</p><p>Goodrich considered both <i>Lithasia jayana</i>, a heavily-shelled
species bearing two rows of spines, and <i>Lithasia duttoniana</i>, a more
lightly-shelled species typically bearing (at most) a single row of small
protuberances, endemic to the rivers from which they were described. <i>Lithasia armigera</i>, as understood by Goodrich,
ranged from the lower Ohio and Wabash Rivers through most of the Cumberland River
and much of the Tennessee River as well.</p><p>In an unpublished report to the U.S. Fish and Wildlife
Service, Davis (1974) suggested that <i>Lithasia</i> be subsumed under the genus <i>Io</i> of
Isaac Lea (1831). Davis then went on to
recognize three smooth-shelled taxa in the Duck River, which do not concern us
here, and two spiny taxa, which he identified as <i>Io armigera duttoniana</i> and <i>Io
armigera jayana</i>. After a period of
comment and revision, Davis’ spiny taxa were offered for review under the
Endangered Species Act in the Federal Register (May 22, 1984) as <i>Lithasia
duttoniana</i> and <i>Lithasia jayana</i>.</p><p>Minton & Lydeard (2003) surveyed mitochondrial CO1
sequence variation in <i>Lithasia</i> populations from the Duck River and many other
river systems of the American southeast. The 4 unique sequences they obtained
from 19 Duck River snails (1 <i>jayana</i>, 4 <i>duttoniana</i>, and 14 of smooth-shelled
taxa, in 9 Genebank submissions) did not resolve into consistent clades. Thus Minton & Lydeard synonymized all
Duck River populations, bearing both smooth and spiny shells, under a single
smooth-shelled nomen, <i><a href="https://www.fwgna.org/species/pleuroceridae/l_genicgenic.html" target="_blank">L. geniculata</a></i> (Haldeman 1840).</p><p>Dillon (2020 b, c) has recently reported, however, a survey
of allozyme variation in Duck River <i>Lithasia</i> confirming Goodrich’s (1940)
hypothesis that populations of the spiny <i>duttoniana</i> form are reproductively
isolated from the more smooth-shelled form, which Dillon followed Goodrich in
identifying as <i>Lithasia geniculata</i>.</p><p>The large and diverse samples of <i>Lithasia</i> analyzed by Dillon
(2020 b, c) were collected incidentally during a survey of the Duck River
mussel fauna conducted by Ahlstedt et al. (2017). In addition to populations bearing shells of
the (smooth-shelled) <i>geniculata</i> form and the lighter, single-spined <i>duttoniana</i>
form, the collections made by Ahlstedt and colleagues at two of their most
downstream sites also contained <i>Lithasia </i>bearing shells of the heavy,
doubly-spined <i>jayana</i> form. Here I
compare those doubly-spined <i>jayana</i> samples to sympatric samples of the
lightly-shelled <i>duttoniana</i> form using gene frequencies three allozyme-encoding
loci.</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGLg6ytEYf5ZzkGjIPDVihKktMnYreGx0ti9Kg1Ieib5eYU-PC98B0Km9r3uqJjwmrjlb7Sdta1BLDA343YI-AjNMhXWpJitATFSWbwP2sgtvivCYTxfOEjQKkGU_SexBBPNkNIojTlB6hOf0f6VNTYRr9aYCIPZCNsrwaVhnIn00j7aM0njHAxLYbtQ/s940/Duck-dut-jay-montage.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="747" data-original-width="940" height="254" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGLg6ytEYf5ZzkGjIPDVihKktMnYreGx0ti9Kg1Ieib5eYU-PC98B0Km9r3uqJjwmrjlb7Sdta1BLDA343YI-AjNMhXWpJitATFSWbwP2sgtvivCYTxfOEjQKkGU_SexBBPNkNIojTlB6hOf0f6VNTYRr9aYCIPZCNsrwaVhnIn00j7aM0njHAxLYbtQ/s320/Duck-dut-jay-montage.jpg" width="320" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Fig. 1. The Duck River, showing sample sites.<br /><br /></span></td></tr></tbody></table>My methodology for the resolution of allozyme polymorphism
by horizontal starch gel electrophoresis has been previously detailed (Dillon
1982, 1985, 1992). For the present
study, variation interpretable as the product of codominant, Mendelian alleles
was resolved at the mannose phosphate isomerase (Mpi) locus using buffers
TrisCit6 and TEB8, at the octopine dehydrogenase (Odh) locus using buffers
TisCit6 and Poulik, and hexanol dehydrogenase (hexdh) using buffers TEB8 and
Poulik.<p>Sample sites and example shells are shown in Figure 1 above. (The shell length of dutF is 24.6 mm; the
other shells are to scale.) At their
most downstream site, site F, Ahlstedt and colleagues collected 35 <i>Lithasia</i> of
the <i>duttoniana</i> form (dutF) and 30 of the<i> jayana</i> form (jayF). This site, the Watered Hollow Boat launch at
Duck River Mile 26.0 (35.9322, -87.7475), was the point at which Minton &
Lydeard (2003) collected their sample of <i>L. jayana</i> for mtDNA sequencing. Upstream at Wright Bend Site E (TNC110, DRM
38.7, 35.8267, -87.6657), Ahlstedt collected 44 <i>Lithasia</i> of the <i>duttoniana</i> form
(dutE) and 40 of the <i>jayana</i> form (jayE).</p><p><i>Lithasia</i> bearing shells of the <i>jayana</i> morphology become
increasingly rare further upstream and are not effectively collectable above
Duck River mile 60. But populations of
the more lightly-shelled <i>duttoniana</i> type extend as far upstream as DRM
186. Gene frequencies in <i>duttoniana</i>
population dutD, collected from the Fountain Creek confluence at DRM 145.5 (TNC
94, 35.5695, -86.9682), are included here for comparison.</p><p>Table 1 below shows that no significant allele frequency
differences were apparent between samples bearing shells of the <i>duttoniana</i> and
<i>jayana</i> forms at either site where they co-occurred. This was true for the Odh locus (chi-square =
0.688, 2 df at site E, chi-square = 1.62, 3 df at site F), the Mpi locus
(Fisher’s p = 0.334 at site F) and the Hexdh locus (Fisher’s p = 0.513 at site
E, p = 0.832 at site F). Judging by Nei
(1978) genetic distance, sample jayE was more genetically similar to sample
dutE (D = 0.050), and sample jayF was more similar to dutF (D = 0.080) than
jayE was to jayF (D = 0.161) or dutE to dutF (D = 0.164).</p><p>Gene frequency differences were very significant
longitudinally, however, at two of the three loci examined. Combining the 44 + 40 = 84 samples from site
E (DRM 38.7) and comparing to the 35 + 30 = 65 samples from site F (DRM 26.0),
chi-square = 26.2 (3 df, p < 0.00001) at the Odh locus and chi-square = 9.91
(1 df, p = 0.002) at the Hexdh locus.
The dutD sample collected upstream at DRM 145.5 also differed
significantly at the Odh locus from the combined site E sample (chi-square =
7.84, 2df, p = 0.02).</p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5VU4_aroseTvYAFigiKmXR8emX3z35D9RyDr2tXRv5V5ZZS3cKY5wVUC0hE7c4OJm_5i4mSmxC2CKG3u4-qzDmATsuY2wYVg3SK6I1GLaTsK3bZPg7Gi_32Q8Dip9i59ORjyyXpIV-V5u7-BsqIJb1WMcFHKLdG4aMTI4WvFFEPwDi4VA8E-dgQwd0w/s2660/dutjay-table.jpg" style="margin-left: auto; margin-right: auto;"><span style="font-size: x-small;"><img border="0" data-original-height="1896" data-original-width="2660" height="228" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5VU4_aroseTvYAFigiKmXR8emX3z35D9RyDr2tXRv5V5ZZS3cKY5wVUC0hE7c4OJm_5i4mSmxC2CKG3u4-qzDmATsuY2wYVg3SK6I1GLaTsK3bZPg7Gi_32Q8Dip9i59ORjyyXpIV-V5u7-BsqIJb1WMcFHKLdG4aMTI4WvFFEPwDi4VA8E-dgQwd0w/s320/dutjay-table.jpg" width="320" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: x-small;">Tab 1. Gene frequencies at three loci in five samples of <i>Lithasia</i>.</span></td></tr></tbody></table><p>These results reflect no evidence of reproductive isolation
between <i>Lithasia </i>bearing the <i>duttoniana</i> shell morphology and those bearing the
<i>jayana</i> shell morphology. The genetic
evidence is strong, however, for isolation by distance among the spiny <i>Lithasia</i>
populations down this length of river, similar in magnitude to that documented
by Whelan et al. (2019) in Alabama <i>Leptoxis</i>, and Dillon (2020a) in North
Carolina <i>Pleurocera</i>.</p><p>The similarity between these results and those previously
published by Dillon (2020b) for the smooth-shelled <i>Lithasia</i> of the Duck River
is striking. Dillon confirmed the
hypothesis of Goodrich (1934) that the shells borne by Duck River <i><a href="https://www.fwgna.org/species/pleuroceridae/l_genicgenic.html" target="_blank">Lithasia geniculata</a></i> also become more robust when sampled in a downstream direction,
adding bumpy shoulders to the point that 19th-century authorities recognized
two additional species, <i><a href="https://www.fwgna.org/species/pleuroceridae/l_genicfulig.html" target="_blank">L. fuliginosa</a></i> and <i><a href="https://www.fwgna.org/species/pleuroceridae/l_genicpinguis.html" target="_blank">L. pinguis</a></i>. Here an identical phenomenon is documented in
the spiny <i>Lithasia</i>, populations identified by Goodrich as <i>Lithasia duttoniana</i>
developing such robust and heavy shell spines downstream that some authorities
have recognized a second species, <i>L. jayana</i>.</p><p>Given such levels of shell variability, neither nominal
<i>Lithasia duttoniana</i> (Lea 1841) nor<i> Lithasia jayana </i>(Lea 1841) can be
distinguished at the specific level from the much more broadly-distributed
<i>Lithasia armigera</i> (Say 1821). The
suggestion of Davis (1974) that both of Lea’s 1841 nomina be lowered to
subspecific status under Say’s <i>L. armigera</i> would seem to have substantial
merit.</p><p><u><br /></u></p><p><u>References</u></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">Ahlstedt, S. A., J. R. Powell, R. S. Butler, M. T. Fagg, D.
W. Hubbs, S. F. Novak, S. R. Palmer and P. D. Johnson. 2017. Historical and
current examination of freshwater mussels (Bivalvia: Margaritiferidae:
Unionidae) in the Duck River basin Tennessee, USA. Malacological Review
45:1-163.</p><p class="MsoNormal">Davis, G.M. 1974.
Report on the rare and endangered status of a selected number of
freshwater Gastropoda from southeastern U.S.A. U.S. Fish & Wildlife
Service. Washington, DC. 51 p.</p><p class="MsoNormal">Dillon, R. T., Jr. 1982. The correlates of divergence in
isolated populations of the freshwater snail, <i>Goniobasis proxima</i> (Say). Ph.D.
Dissertation, The University of Pennsylvania.</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">Dillon, R. T., Jr. 1985. Correspondence between the buffer
systems suitable for electrophoretic resolution of bivalve and gastropod
isozymes. Comparative Biochemistry and Physiology 82B: 643-645. [<a href="https://www.fwgna.org/dillonr/dillon85.pdf" target="_blank">pdf</a>]<o:p></o:p></p>
<p class="MsoNormal">Dillon, R. T., Jr. 1992. Electrophoresis IV, nuts and bolts.
World Aquaculture 23(2):48-51.<o:p></o:p></p>
<p class="MsoNormal">Dillon, R. T., Jr. 2020a. Fine scale genetic variation in a
population of freshwater snails. Ellipsaria 22(1): 24-25. [<a href="https://www.fwgna.org/dillonr/dillon-ellipsaria-22-1.pdf" target="_blank">pdf</a>]<o:p></o:p></p>
<p class="MsoNormal">Dillon, R. T., Jr. 2020b. Population genetic survey of
<i>Lithasia geniculata</i> in the Duck River, Tennessee. Ellipsaria 22(2):19 – 21. [<a href="https://www.fwgna.org/dillonr/dillon-ellipsaria-22-2.pdf" target="_blank">pdf</a>]<o:p></o:p></p>
<p class="MsoNormal">Dillon, R. T., Jr. 2020c. Reproductive isolation between
<i>Lithasia</i> populations of the <i>geniculata</i> and <i>duttoniana</i> forms in the Duck River,
Tennessee. Ellipsaria 22(3): 6 – 8. [<a href="https://www.fwgna.org/dillonr/dillon-ellipsaria-22-3.pdf" target="_blank">pdf</a>]<o:p></o:p></p>
<p class="MsoNormal">Goodrich, C. 1934. Studies of the gastropod family
Pleuroceridae - I. Occasional Papers of the Museum of Zoology, University of
Michigan 286:1-17.<o:p></o:p></p>
<p class="MsoNormal">Goodrich, C. 1940. The Pleuroceridae of the Ohio River
drainage system. Occasional Papers of the Museum of Zoology, University of
Michigan 417:1 - 21.<o:p></o:p></p>
<p class="MsoNormal">Minton, R. L. and C. Lydeard. 2003. Phylogeny, taxonomy,
genetics, and global heritage ranks of an imperiled, freshwater snail genus
<i>Lithasia</i> (Pleuroceridae). Molecular Ecology 12:75-87.<o:p></o:p></p>
<p class="MsoNormal">Nei, M. 1978 Estimation of average heterozygosity and
genetic distance from a small number of individuals. Genetics 89:583–590.<o:p></o:p></p>
<p class="MsoNormal">Whelan, N. V, M. P. Galaska, B. N. Sipley, J. M. Weber, P.
D. Johnson, K. M. Halanych and B. S. Helms. 2019. Riverscape genetic variation,
migration patterns, and morphological variation of the threatened Round
Rocksnail, <i>Leptoxis ampla</i>. Molecular Ecology 28:1593-1610.</p><p class="MsoNormal"><br /></p><p class="MsoNormal"><u>Notes</u></p><p class="MsoNormal"><b><span style="color: #783f04;">[1]</span></b> Here is the relevant passage from the minutes of the
FMCS Board, November 19, 2020:</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"></p><blockquote><span style="font-size: x-small;">“Nathan Whelan noticed recently that some Contributed
Articles in Ellipsaria are now findable on Google Scholar. This was unexpected for our informal,
non-peer-reviewed newsletter. Nathan also recognized that some recent articles in the
newsletter include the analysis of data and/or what could be viewed as proposed taxonomic revisions.
In a series of emails, monitored and, occasionally, participated in by the Executive Committee,
Nathan and Ellipsaria Editor John Jenkinson agreed that articles including data analysis
and/or taxonomic revisions should be peer-reviewed and, therefore, are outside of the intended
scope and purpose of our newsletter.”</span></blockquote><p></p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal"><span style="color: #783f04;"><b>[2]</b><b> </b></span>Science is the construction
of testable hypotheses about the natural world.
It is not the handing down of fact.
It appeals to no authority, nor does it merit any. It is independent of context or culture. Whether published in a slick international
journal or a humble newsletter is irrelevant.
The quality of a work of science is dependent only upon the extent to
which the hypothesis proposed matches the natural world, upon rigorous
test. And it stuns me – literally stuns
me – to see how few scientists actually understand any of this.<o:p></o:p></p>Rob Dillonhttp://www.blogger.com/profile/09916618545870123585noreply@blogger.com0