Goodbye Goniobasis, Farewell Elimia

Editor's Note.  This essay was subsequently published as: Dillon, R.T., Jr. (2019c) Goodbye Goniobasis, Farewell Elimia.  Pp 19-22 in The Freshwater Gastropods of North America Volume 3, Essays on the Prosobranchs.  FWGNA Press, Charleston.

The systematic relationships among Pleurocera, Goniobasis, Elimia, and several other nominal genera of slender pleurocerids in eastern North America first rose to our attention in February of 2007 (1). Faithful readers may remember the post to this blog entitled “Goodrichian Taxon Shift,” in which I reported a survey of gene frequencies in a pleurocerid population inhabiting Indian Creek, a small river in the remote southwestern corner of Virginia. The shell morphology demonstrated by that particular population varied from the slender and carinate “Goniobasis acutocarinata” form in the headwaters to the smooth and more heavily shelled Goniobasis clavaeformis form in the main creek itself. And at the mouth, where Indian Creek emptied into the Powell River, the shell morphology of this single population of pleurocerids became so chunky as to appear to change genera, to “Pleurocera unciale.”

I returned to this subject in October of 2009 under the title “Pleurocera Puzzles” (2). In that second post I reported an extension of my Indian Creek study to include pleurocerid populations inhabiting three additional subdrainages: the Pistol/Little River near Maryville (TN), the Conasauga/Hiwassee River east of Etowah (TN), and the Coahulla/Oostanaula River in North Georgia. In all four cases, the populations of Pleurocera inhabiting downstream reaches were more genetically similar to the local “Goniobasis” populations immediately upstream than to other nominal Pleurocera populations. This would seem to confirm that the shell attributes by which Pleurocera and Goniobasis have historically been distinguished cannot stand.

Taxonomic controversies have simmered within the tiny, closely knit scientific community working on the North American Pleuroceridae since the birth of American malacology. In my blog post of November 2010, I reviewed the longstanding disagreements over the generic nomina Pleurocera, Lithasia, and Oxytrema, which continued through most of the 20th century (3). More visible recently has been the controversy regarding the generic nomina Goniobasis and Elimia, which I reviewed in a blog post way back in September of 2004 (4).

We’ve been beating each other up over whether to call these populations Pleurocera, Oxytrema, Goniobasis, Elimia, and God Knows What Else for almost 200 years, and there’s never been a nickel’s worth of biological difference in the lot of them (5). Let’s put all this behind us, shall we?

The research results I telegraphed to this group in October 2009 have just been published in the issue of Malacologia currently on the newsstands. In Appendix 1 of that paper I formally synonymize Goniobasis, Elimia, and eight more obscure genera under the genus Pleurocera (Rafinesque, 1818). A pdf download is available from link (6) below. See pp 276 - 77.

The FWGNA site has been completely updated to correct all primary instances of the generic nomen “Goniobasis” to the most recent taxonomy (7). I would invite my colleagues to do likewise with the generic nomen, “Elimia.” Let the peace of Pleurocera begin.

Notes

(1) Goodrichian Taxon Shift [20Feb07].

(2) Mobile Basin III: Pleurocera Puzzles [12Oct09]

(3) Joe Morrison and the Great Pleurocera Controversy [10Nov10]

(4) Goniobasis and Elimia [28Sept04]

(5) DAZO, B.C. (1965) The morphology and natural history of Pleurocera acuta and Goniobasis livescens (Gastropoda: Cerithiacea: Pleuroceridae). Malacologia 3:1-80. STRONG, E.E. (2005) A morphological reanalysis of Pleurocera acuta Rafinesque, 1831, and Elimia livescens (Menke, 1830) (Gastropoda: Cerithioidea: Pleuroceridae). Nautilus 119:119-132.

(6) Dillon, R. T., Jr. (2011) Robust shell phenotype is a local response to stream size in the genus Pleurocera (Rafinesque, 1818). Malacologia 53: 265-277. [PDF]

(7) I did not change the file names, only the html text. Even so, the process took several days, and I’m still not sure I've caught every instance. If you find any stray “Goniobasis” in the text of the FWGNA site, let me know.

When Art and Science Collide

Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023c)  When Art and Science Collide.  Pp 335 – 338 in The Freshwater Gastropods of North America Volume 7, Collected in Turn One, and Other Essays.  FWGNA Project, Charleston, SC.

Last fall I received an unusual email from Mr. Mark Wentzel, a sculptor living in the Atlanta area, bearing the subject line “L. columella.” Mr. Wentzel explained that he was working on an art exhibition for the Rollins School of Public Health at Emory University, and inquired whether there might be “a source for ordering Lymnaea columella shells,” or if not, advice as to “a good method (or locality) of obtaining one. I was intrigued.

Connections between the Mollusca and the visual arts have a long and lavish history. Seashells, in particular, become decorative items almost untouched by the hand of man, save for a good cleaning. Entire coffee-table books have been dedicated to seashells as adornment in the primitive peoples, seashell motifs in the works of the renaissance masters, sailor’s valentines, X-ray photographs, and so forth. Upon entering the church of St. Sulpice in Paris, one finds the holy water contained in a massive pair of Tridacna valves, gifts from Venice to Francis I. How they got to Venice in the early 16th century, God knows.

Freshwater gastropods, however, are not decorative. One could certainly fashion the image of a freshwater snail into a logo and put it on a tee shirt. But I cannot (off the top of my head) think of any works of visual art, intended to stand alone, featuring our favorite creatures.

So I struck up an email correspondence with Mr. Wentzel to learn more about his project. Fishing for a connection to public health, I asked if his interest in L. columella might be somehow tied to the potential of lymnaeids to host fascioliasis. He replied that “Fascioliasis comes into play, but mostly as a metaphor.” More directly, the work he was contemplating “involves water, a Vietnam era Mk2 hand-grenade, a four-gallon Mason, lead drinking cups, and the unfamous (sic) L. columella, an indirect nod to Lucius Junius Moderatus Columella, the Roman author of De Re Rustica, including significant early contributions to the field of food preservation.”

Mr. Wentzel added, almost as an afterthought, “My choice of L. columella was no fluke.” Okay, that got me. I sent him a sample of L. columella in the next morning’s “snail mail.”

The exhibition opened in December, under the title “4 Fields: Science and Environmental Health from a Creative Point of View.” [Click the image above to read the flyer.] I have not been to Atlanta to view the works first hand, but my overall impression, judging from the brochure, is that it is complicated. The title was “borrowed from the concept of the four sub-fields of anthropology” which turn out to be (according to Wikipedia) physical anthropology, cultural anthropology, archaeology, and linguistics. The connection between anthropology, sculpture, and environmental health is obscure to me. As well as many other things.



The figure above shows Mark Wentzel's entire work [click for enlargement]. Our Lymnaea columella shells have been given rubbery little bodies and affixed to the tip of a Pasteur-style swan-necked flask at the far left. The hand grenade appears as a spigot for the 4-gallon mason. A close-up of the most exciting part of the piece is shown below.

The next paragraph is going to be boring and obvious, but bear with me. I’m getting ready to make a point.

Art and Science are two entirely different things. Mark Wentzel works in a world with its own unique language, culture, and set of values that are entirely different from, no better and no worse than, the world in which I live. This does not mean that artists and scientists cannot work together. Our worlds are not incompatible. But neither are our worlds compatible in any sense, either. They are just completely, utterly different.

Now scratch out the word "art" in the paragraph above, an insert the phrase, “law and public policy.” The paragraph will remain just as true. Science is no more compatible with public policy than it is with fine art.

Last month I got a (rather routine) email from a DNR biologist working on a revision of the South Carolina priority conservation invertebrate species. He wanted to know what freshwater gastropods in our state might be “of conservation concern.” So I pointed him to Table 1 on the Freshwater Gastropods of South Carolina website, where all 32 of our species are ranked by their abundances at many hundred sampling sites. My own (completely subjective) opinions regarding which of those species might warrant some conservation concern are to be found under "Recommendations" on that same site.

But in a larger sense, the concept of "conservation concern” in law is no more scientific than the concept of “beauty” in the fine arts. Neither can be measured, and hence science has nothing to say about either.

I was happy to send data to our DNR biologist, just as I was happy to send Mr. Wentzel some shells of L. columella. But I would never dream of pretending that science figures into my interactions with the latter world. Why do we continue to imagine that science can enter into the former?

Mollusk Session in Albany, Apr. 6 - 9

Our good friend Dave Strayer is organizing a special session on mollusks at the NNHC meeting in Albany this April. See Dave's email below for further details, as well as a link to the conference web site.

Looks like a lot of fun!
Rob

From: Dave Strayer strayerd@caryinstitute.org
To: Rob Dillon dillonr@cofc.edu
Date: Fri, 7 Jan 2011 11:41:13 -0500
Subject: Northeast Natural History Conference

Hello everyone-

I am organizing a special session on mollusks at the Northeast Natural History Conference, which will be held in Albany (NY) on 6-9 April 2011. If you are interested in contributing a paper or poster to this session (the session is called “Freshwater Malacology” right now, but I’d be happy to include presentations on marine or terrestrial mollusks), please go to http://www.eaglehill.us/NENHC_2011/NENHC2011 for information about the conference and forms for registering and submitting an abstract. Or, if you have questions or are feeling shy about joining this session, you can email me at strayerd@caryinstitute.org.

The Northeast Natural History Conference is a friendly and lively conference that is held every 2 years at the New York State Museum in Albany. It attracts all kinds of ecologists, conservationists, taxonomists, etc. from throughout the Northeast, and is a fun and simulating conference. I think it’s an especially good and non-threatening place for students or amateurs to give presentations. If you visit the conference web site, you’ll see that there is an attractive slate of workshops in addition to the usual talks and posters.

If you’re working on mollusks in the Northeast, I hope that you’ll think about contributing to this special session. The deadline for submitting an abstract is 1 March 2011, so ACT NOW!!

Please pass this notice along to anyone who might be interested.

Dave Strayer

Two Species of Ferrissia

Editor's Note.  This essay was subsequently published as: Dillon, R.T., Jr. (2019b)  Two species of Ferrissia.  Pp 143-147 in The Freshwater Gastropods of North America Volume 2, Essays on the Pulmonates.  FWGNA Press, Charleston.

Back in June of 2009, when last we touched on the systematics of ancylid limpets in North America, we were standing at a crossroads (1). Paul Basch’s monograph, which has formed the basis of our understanding of the group for many years, lists five species in the widespread genus Ferrissia: rivularis, fragilis, parallela, mcneilli and walkeri (2). But the DNA sequence data of Andrea Walther (at that time unpublished) suggested that only F. rivularis and F. fragilis were at all genetically distinct, subsuming parallela under the former nomen, and mcneilli and walkeri under the latter.

Then in the spring of 2009 came the freshly-published allozyme data of Dillon & Herman (3) demonstrating that South Carolina populations of Ferrissia were reproducing entirely by self fertilization, “voiding the biological species concept, and necessitating a retreat to the morphological.” And along with our allozyme data came the results of common-garden experiments suggesting that the morphological criteria by which F. rivularis and F. fragilis had previously been distinguished were ecophenotypic in origin. So in the absence of evidence that any morphological distinction might have a heritable component, Dillon & Herman synonymized the nomen F. fragilis under F. rivularis, leaving North America with but a single species of Ferrissia.

I am now pleased to report that Andrea Walther, together with her colleagues Jack Burch and Diarmaid O’Foighil, has cast additional light on this situation (4). Writing in the issue of Malacologia currently on the newsstands, the team from Ann Arbor has been able to correlate apparently reliable features of the Ferrissia shell apex with their DNA sequence data, pulling fragilis back out from synonymy under rivularis.

Populations of F. rivularis, in our newly clarified understanding of that taxon, bear shells in which the apex is unambiguous – the cap of the earliest (juvenile) shell remains at the tip of the conical shell of the adult – generally at the midline or very near it [photo at left above - click for larger]. But in populations of F. fragilis, the juvenile shell cap is not at the apex of the adult shell, but rather is located slightly below and to the right of the midline [photo right - click for larger].

Under the older (Basch) concepts of the species (5), populations of F. rivularis were understood to inhabit rocky streams throughout the Blue Ridge ecoregion east into the upper Piedmont of all four southern Atlantic states. Ferrissia fragilis populations were restricted to vegetation and debris in calmer rivers, ditches and swamps in the lower Piedmont and Coastal Plain.

In our newly clarified understanding, however, almost all the Ferrissia populations inhabiting southern Atlantic drainages appear referable to F. fragilis alone, including those bearing quite robust shells inhabiting high-gradient streams in the Blue Ridge.

The only populations of bona fide F. rivularis in southern Atlantic drainages appear to inhabit tributaries of the Potomac River in Northern Virginia, ranging south up the Great Valley into the upper James and Roanoke drainages. This much more restricted range for F. rivularis becomes rather strikingly similar to that of Physa gyrina, another pulmonate snail more characteristic of the American interior, especially in northern latitudes.

Ancylid limpets are among the most common and familiar elements of the North American freshwater macroinvertebrate fauna. It is oddly reassuring to see our understanding of such fundamental aspects of their biology shift in just a few years; indeed, in a matter of months. Our science is an active one. For that, we should be thankful.


Notes
(1) Just One Species of Ferrissia [10June09]

(2) Basch, P.F. (1963) A review of the recent freshwater limpet snails of North America (Mollusca: Pulmonata). Bull. Mus. Comp. Zool. Harvard Univ. 129: 399–461.

(3) Dillon, R. T. and J. J. Herman (2009) Genetics, shell morphology, and life history of the freshwater pulmonate limpets Ferrissia rivularis and Ferrissia fragilis. Journal of Freshwater Ecology 24: 261-271. [PDF]

(4) Walther, A. C., J. B. Burch and D. O’Foighil (2010) Molecular phylogenetic revision of the freshwater limpet genus Ferrissia (Planorbidae:Ancylinae) in North America yields two species: Ferrissia (Ferrissia) rivularis and Ferrissia (Kincaidilla) fragilis. Malacologia 53: 25-45.

(5) To be fair, Basch did notice differences in the apex of his five Ferrissia species. For F. rivularis, his couplet specified "apex in midline or slightly to the right." He attributed "apex subacute, often far in the right posterior quadrant" to F. walkeri. Regarding the apex of F. fragilis, however, he was silent.

Joe Morrison and the Great Pleurocera Controversy

Editor's Note.  This essay was subsequently published as: Dillon, R.T., Jr. (2019c) Joe Morrison and the great Pleurocera controversy.  Pp. 11-18 in The Freshwater Gastropods of North America Volume 3, Essays on the Prosobranchs.  FWGNA Press, Charleston.

One of the more vivid memories I carry with me from my early days in this profession comes from the 1979 meeting of the American Malacological Union in Corpus Christi, Texas. The paper I had just presented that August morning was essentially the first chapter of my dissertation – an allozyme survey of twelve Goniobasis populations from the mountains of Virginia and North Carolina (1). And up from his seat in the back of the room jumped “Old Joe” Morrison, red-faced and shivering with rage.

J. P. E. Morrison was 72 years old in the summer of 1979, retired from the Smithsonian for about four years, but nevertheless a large and imposing figure (2). He launched into a rambling but passionate tirade about the meaning of the generic nomen “Pleurocera,” oscillating wildly from 19th century historical chronologies to egg mass morphologies, glowering at me and daring me to defy him. I don’t remember the details of my response, but I do remember beginning with, “Easy, big fella.”

Old Joe’s passion was, for me at the time, difficult to comprehend. But in subsequent years I have come to realize that we were witnessing a rehearsal of The Great Pleurocera Controversy, a conflict rooted deeply in the parent rock of American Malacology, passed to Morrison (and me!) through many generations of malacologists gone before. Our story begins in 1818, when the eccentric polymath Constantine S. Rafinesque (3) published the nomen “Pleurocera” as a genus to contain six species of freshwater prosobranch gastropods, none of which he described. Then in 1819 Rafinesque proposed “Oxytrema” as a genus to contain a second set of species including what we have some reason to think may have been what is known today as Pleurocera canaliculata [Photo at right].

Joe Morrison strongly felt that the actual text of Rafinesque’s 1818 description (4) most closely fit the chunky, bumpy shell morphology of what is known today as Lithasia verrucosa [Photo below]. But by common use through the 19th century and into the 20th, the generic nomen “Pleurocera” became attached to (or perhaps transferred to?) snails bearing smooth, skinny shells like what is known today as Pleurocera canaliculata, or (biologically equivalent, see Note 5) Pleurocera acuta. And the chunky-bumpies became Lithasia, and the nomen “Oxytrema” fell into disuse. And the family name that ultimately prevailed for the entire group of freshwater snails was based on the smooth-skinny concept of the genus, “Pleuroceridae.”

Despite the ancient origins of this confusion, however, the Great Pleurocera Controversy was very much a phenomenon of the 20th century. It sparked in 1912, when Harold Hannibal designated the chunky-bumpy verrucosa as type of the genus Pleurocera, and burst into flame in 1917, when Henry Pilsbry agreed with Hannibal, and Bryant Walker [15] rose to defend the cause of the smooth-skinnies (6). Pilsbry appealed to the International Commission on Zoological Nomenclature for a ruling in 1925.

The case simmered in court for 55 years (7), during which time Calvin Goodrich pretty much monographed the entire North American Pleuroceridae in bits and pieces, using the nomen Pleurocera in its smooth-skinny sense, essentially deciding the issue (8). Along the way, comments supporting the smooth-skinny concept of Pleurocera were filed by Joshua Bailey, Emilio Berio, Arthur Clarke, Joe Rosewater, Henry van der Schalie, Billy Isom, and George Davis. Comments supporting the chunky-bumpy concept were filed by Dave Stansbery, Carol Stein, and Joe Morrison.

The historical minutiae around which the case ultimately revolved were complex. Toward the end of the controversy, some of the arguments made by Morrison and his allies were so arcane that one commissioner complained that they looked “suspiciously like sabotage.” But Morrison was not to prevail. On 4Nov1981 the ICZN handed down Opinion 1195, ruling in favor of the smooth-skinny concept of Pleurocera by a vote of 19-3 (9).

So was it simply a question of taxonomic priority between two Rafinesque names of 1818 and 1819 that brought Old Joe to his feet on that August morning in 1979, red-faced with rage? Rafinesque had been in his grave for 139 years, and does not seem to have cared which of his names was used during his own lifetime, in any case. And I had not even mentioned the genus Pleurocera during my entire 15 minute presentation – my paper was about Goniobasis only.

No. To fully appreciate the issues at stake in The Great Pleurocera Controversy, we must roll the clock back once again to 1954, and the publication of what may have been Joe Morrison’s most important contribution to science, “The Relationships of Old and New World Melanians” (10).

Morrison’s (1954) work can only be appreciated through 19th century goggles. His introduction began with a statement of his hypothesis as an unquestionable fact, and a dismissal of any other hypothesis as “biological absurdity.” Morrison asserted that there are three freshwater cerithiacean families, each of which has evolved separately from marine ancestors: the Pleuroceridae from the Cerithidae, the Thiaridae from the Planaxidae, and the Melanopsidae from the Modulidae. He then reviewed the entire worldwide fauna of freshwater cerithiacean snails in 28 pages of text, focusing first on their taxonomy, and second on their reproductive biology, especially egg laying habit. He concluded his paper with a single plate of original observations, almost entirely external right-side sketches of extended females, showing egg laying grooves or brood pouches.

This was a tremendously ambitious work – the first worldwide review of the freshwater cerithiacean gastropods. By the standards of such contemporaries as Bengt Hubendick (11), it was embarrassingly slapdash. But in comparison with the much older, regional monographs it sought to review and synthesize, such as that of Tryon 1873, it was an improvement.

And to my eyes, the most significant innovation that Morrison introduced to the classification of the freshwater cerithiacean fauna worldwide in 1954 was his concept of a genus that he called “Oxytrema.” Morrison advocated combining all the sexually reproducing freshwater cerithiaceans bearing tall skinny shells … not just the species that Walker & Goodrich assigned to Pleurocera but also those they called Goniobasis (and Juga from the American West, and even many East Asian species) into this single gigantic genus on the basis of female reproductive habit. He wrote:

“Oxytrema Rafinesque is the earliest and correct name for one of the most widespread "Melanian" genera in the world. This genus includes numerous North American species whose ranges extend from the Atlantic to the Pacific coasts and from southern Canada to Florida and Texas. It also includes North American fossils, as well as a number of Recent species from southeast Asia (Korea, China, and Thailand). All the species called "Pleurocera" by Bryant Walker, and other authors who followed him blindly, and the species called "Goniobasis" (with very few exceptions) belong to this genus. Their eggs are laid in a single row in a close, irregularly spiral group, in apparent flat clusters of 3 to 10 egg capsules in each small egg mass, the whole covered with sand grains."

So now we understand, at long last, how a 24-year old graduate student could incur the Wrath of Joe on an August morning in 1979 simply by referring to a genus named “Goniobasis.” Morrison needed the 1819 Rafinesque nomen Oxytrema to legitimize a massive, worldwide taxonomic revision, pushing Goniobasis underneath it, even as he needed to save the name Pleurocera by pushing it aside for another use.

Old Joe died in 1983. I remain, to this day, unable to assess the validity of his taxonomic arguments, but in the wake of the 1981 decision of the ICZN, they have become moot (12). Portions of his biological argument, however, seem to have considerable merit on the basis of much more than eggs. A paper supporting the combination of Pleurocera (as we know it today) and Goniobasis had already been published in 1965 by B. C. Dazo, hailing from Ann Arbor (of all places), the home of Walker and Goodrich. And Dazo’s results have more recently been confirmed and expanded by Ellen Strong (13).

And faithful readers of this blog may remember my posts of 20Feb07 and 12Oct09, demonstrating that shell morphology within a single population of pleurocerids can range from Goniobasis-like to Pleurocera-like as a correlate of stream size, probably a consequence of ecophenotypic variation (14). Might a measure of posthumous vindication for Old Joe Morrison yet be in store?

Stay tuned…
Rob


Notes

(1) Subsequently published as: Dillon, R. T., Jr & G. M. Davis (1980) The Goniobasis of southern Virginia and northwestern North Carolina: Genetic and shell morphometric relationships. Malacologia 20: 83-98. [pdf]

(2) The photo of Morrison above was downloaded from what amounts to his obituary, although it was not advertised as such: Rosewater, J. (1984) A bibliography and list of taxa of Mollusca introduced by Joseph P. E. Morrison Dec 17, 1906 – Dec. 2, 1983. The Nautilus 98: 1-9.

(3) The life of C. S. Rafinesque (1783 - 1840) is the stuff of legend. Google his name and see what I mean. An (1864) work by W. G. Binney and G. W. Tryon entitled, "The Complete Writings of Constantine Smaltz Rafinesque on Recent & Fossil Conchology" is available from the Biodiversity Heritage Library website, if you're hungry for more.

(4) From Binney & Tryon: "Univalve. Shell variable oboval or conical, mouth diagonal crooked, rhomboidal, obtuse and nearly reflexed at the base, acute above the connection, lip and columella flexuose entire. Animal, with an operculum membranaceous, head separated from the mantle inserted above it, elongated, one tentaculum on each side at its base, subulate acute, eyes lateral exterior at the base of the tentacula."

(5) Although populations of the snails identified as Pleurocera acuta today [photo right] are biologically quite similar to populations of the snails we currently identify as P. canaliculata, the specific nomen “acuta” became almost as entangled taxonomically as the generic nomen “Pleurocera.” Ultimately “Pleurocerus acutus” was chosen as the type of the genus. See Opinion 1195 (Note 9) for the gory details.

(6) Pilsbry, H. A. (1917) Rafinesque's genera of freshwater snails. Nautilus 30: 109-114. Walker, B. (1917) The type of Pleurocera Rafinesque. Occas. Pprs. Mus. Zool. Univ. Mich. 38: 1 - 10.

(7) Secretary R. V. Melville offered a detailed apology for the extraordinary delays suffered in the resolution of the Pleurocera question in Opinion 1195 (Note 9).

(8) For more see my previous blog post: The Legacy of Calvin Goodrich [23Jan07]

(9) Melville, R. V. (1981) Opinion 1195. Pleurocera Rafinesque, 1818 (Gastropoda): The type species is Pleurocerus acutus Rafinesque in Blainville, 1824. Bulletin of Zoological Nomenclature 38: 259-265.

(10) Morrison, J. P. E. (1954) The relationships of Old and New World Melanians. Proc. U. S. Nat. Mus. 103: 357- 394.

(11) For more about Bengt Hubendick, see my previous blog posts: The Classification of the Lymnaeidae [28Dec06] The Classification of the Planorbidae [11Apr08]

(12) But it is not a stretch to view the ongoing Goniobasis/Elimia taxonomic controversy as a consequence of the Pleurocera controversy that preceded it. J. B. Burch rationalized his decision not to apply to the ICZN for conservation of the more familiar Walker & Goodrich nomen Goniobasis over the Pilsbry Elimia by referring to the "inordinate amount of time" required to reach an opinion on Pleurocera. For more see my post on Goniobasis and Elimia [28Sept04].

(13) Dazo, B. C. (1965) The morphology and natural history of Pleurocera acuta and Goniobasis livescens (Gastropoda: Cerithiacea: Pleuroceridae). Malacologia, 3: 1-80. Strong, E. E. (2005) A morphological reanalysis of Pleurocera acuta Rafinesque, 1831, and Elimia livescens (Menke, 1830) (Gastropoda: Cerithioidea: Pleuroceridae). Nautilus, 119: 119-132.

(14) See my previous blog posts: Goodrichian Taxon Shift [20Feb07] Mobile Basin III: Pleurocera Puzzles [12Oct09]

[15] Note added subsequently.  In my post of [9Nov12] I elaborate at some length on Bryant Walker's Sense of Fairness.

Live Shipping Freshwater Snails

Earlier last month a question was posed to the MOLLUSCA list server on a topic that would seem to be of special interest to our group. Here's the initial query from Dr. Russell Wyeth of St. Francis Xavier University up in Nova Scotia, together with my reply:

I'm curious what advice people have for shipping live Lymnaea stagnalis and their eggs. I've heard that damp paper towels in a plastic box with plenty of holes in the top, and placed inside a cardboard box with little tape is good. Any other suggestions for what has worked (or hasn't worked)?

Thanks,
Russell

Dear Russell,

Yes, the general approach you suggest works very well to ship freshwater snails of all species.

Rather than a "plastic box with plenty of holes in the top," I'd suggest an unbreakable container with a tight-fitting lid. You really don't want water leaking from your paper towels and seeping out of your package. The best containers I've found are those wide-mouthed plastic peanut butter jars.

I admit to being a little bit paranoid about possible leaching from commercial paper towels. So I pre-soak a big wad of paper towels in pond water, wring that out, and then transfer the paper towels in a second (fresh) bucket of pond water, and wring them out a second time.

Stuff a bunch of wet paper towels in the bottom of your peanut butter jar, then the snails, then a bunch more wet paper towels, and then screw the lid on tightly. But be careful with the stuffing! Lymnaeids, as I'm sure you are aware, have very fragile shells. Ideally, you want the snails immobilized, but not crushed.

Yes, pack that peanut butter jar in a larger cardboard box for shipment, with some bubble wrap or packing "peanuts." But no, don't use "little" tape - use "plenty of" tape. You seem concerned that not enough air will get into your snails. Really, just the opposite is the problem - it's drying you need to worry about. Tape that box up well! And spend the extra money for overnight shipment.

Good luck!
Rob

---o---

Dr. Wyeth's question seemed more directed toward the packing, not toward the actual process of shipment, once packed. But some of you may remember my essay on the travails of importing live freshwater snails into the United States back on 17Dec08. I also have a nightmare story about exporting American Helisoma live to a colleague in Italy a couple years ago that I might share one day, if the mood strikes.

In subsequent correspondence, Dr. Wyeth shared with me private replies from of two other colleagues, both offering slight variations on our same theme. One suggested snails -> wet paper towels -> box with holes -> heavy plastic bag with knot. Another offered snails -> wet newspapers -> two layers of plastic bags -> Styrofoam cooler with ice packs.

I agree that the idea of shipping in a Styrofoam cooler has some attraction, depending on the time of year, but might increase the cost substantially.

I also agree with Dr. Wyeth that data on failures might be as useful as data on successes in addressing his question. If anybody has any experience regarding shipments of freshwater snails cooked by excessive heat or dehydrated by leaking containers, feel free to share below!

And keep in touch,
Rob

Valvata utahensis and Hypothesis #2 (of 3)

Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2019d) Valvata utahensis and Hypothesis #2 (of 3).  Pp 159 - 163 in The Freshwater Gastropods of North America Volume 4, Essays on Ecology and Biogeography.  FWGNA Press, Charleston.

Late last month, after many years of research, consultation, and study (1), the US Fish & Wildlife Service announced a finding that Valvata utahensis no longer warrants protection under the federal endangered species act. Quoting directly from the 25Aug10 press release (2), “The decision was made based on new scientific information that demonstrates the snail is more widely distributed and occurs in more habitat types than was known at the time the species was listed.”

Valvata utahensis was one of five freshwater gastropods from southern Idaho to enter the federal list on December 14, 1992. (Image at left from the USDA Rocky Mt. Res. Station). At the time, it was believed to occur “in a few springs and mainstem Snake River sites in the Hagerman Valley and at a few sites below American Falls Dam” in “deep pools adjacent to rapids or in perennial flowing waters associated with large spring complexes” (3). But subsequent status surveys have documented a range extending down 255 miles of the Snake River and across much greater variety of habitat types (4). In fact, V. utahensis seems to be found more abundantly in the impoundments behind the reservoirs than in the free-flowing river itself.

In many respects this episode has been quite similar to that involving the Snake River population of Pyrgulopsis robusta, which entered the US Endangered Species list on the same date as V. utahensis, preceding its removal by three years. Originally listed as “Pyrgulopsis idahoensis,” the Idaho Springsnail was believed to occur “at a few sites from the headwaters of C. J. Strike Reservoir at river mile 518 upstream to approximately river mile 553” (3). But several years of directed surveys found the Pyrgulopsis population actually extending over 80 river miles at an average density of 130/m2, making it one of the largest freshwater snail populations ever documented. And broader systematic research showed that the Snake River Pyrgulopsis was not endemic, but rather ranged across portions three other western states, under several older aliases (5).

Our understanding of the Snake River Pyrgulopsis progressed through a complete three-hypothesis evolution, from (#1) narrow endemic to (#2) regional endemic to (#3) non-endemic, as information accumulated. It appears that progress in Valvata research will be attenuated at Hypothesis #2, which is something of a shame. R. E. Call originally described utahensis as a variant of the much more widely-distributed Valvata sincera (6), and the shell characters on the basis of which Walker elevated utahensis to the specific level (7) are notoriously variable. But with the species delisted on the basis of Hypothesis #2, I fear that the interest of funding agencies in the more evolutionarily-interesting Hypothesis #3 will inevitably wane.

Meanwhile, our understanding of the “Snake River Physa” skipped from the hypothesis of narrow endemicity directly to non-endemic, without ringing the doorbell of Hypothesis #2 at all. After entering the list on 14Dec92 as “Physa natricina,” research on these enigmatic populations suffered an extended period of neglect, due both to the difficulty that field workers have encountered distinguishing it from commonplace Physa gyrina, and to the assumption that no Physa of any interest could easily be sampled from the shallows. So in December of 2007 the Snake River Physa hopped directly from narrowly endemic in deep water and strong currents from “Grandview (RM 492) upstream through the Hagerman Reach (RM 573)” to synonymy under the cosmopolitan Physa acuta, common in marginal and shallow habitats across six continents (8).

This was also a bit of a shame, from the standpoint of academic malacology. Although not anybody’s favorite hypothesis, it is certainly possible that some physid bearing a type-C penial morphology, but not correctly identified as either P. natricina or as P. acuta, might inhabit rivers of the Pacific Northwest. Judging from secondary sources, there seem to be at least two names that might apply to physids of the acuta type in the Snake/Columbia River system regionally, Physa concolor Haldeman 1843 (type locality = “Oregon”) and Physa columbiana Hemphill 1890 (type locality = Columbia R. at Astoria, OR). If we’d spent a few years exploring Hypothesis #2 for the Snake River physids, at least we’d have a bit more information about the ecology and evolution of the pulmonate fauna in an otherwise benighted part of the world.

It may yet happen. “Physa natricina” remains on the federal list of endangered species today, three years after its synonymization under P. acuta. And the “species profile” maintained by the FWS (9) contains an enigmatic reference to a population “as far downstream as Ontario, Oregon (RM 368).” Heaven knows what sort of elaborate processes would be required to effect the delisting of P. natricina (10), and whether it will prove to anybody’s political interest to undertake the task. I am quite certain, however, of one thing.

Over the last 20 years, literally thousands of man hours have been spent on surveys of the Snake River narrowly focused on particular target species, first Pyrgulopsis and more recently Valvata, and Taylorconcha serpenticola, which was also listed in 1992 and also spent many subsequent years in limbo (11). Hundreds of river miles have been traced and retraced and re-retraced, and nobody over all these years as far as I can determine has ever picked up a Physa. If some agency now finds it in the budget to fund yet another survey of the Snake River, this time for the physids, it would be helpful if the biologists involved were to sample the complete gastropod fauna, common and rare, for God’s sake, for a change. And share those results with the entire community.

Twenty years of wandering in the malacological wilderness of southern Idaho were touched off in 1992 by boneheaded spot-sampling (12). One might hope that we would, eventually, learn.

Notes

(1) I first featured the ongoing FWS “Comprehensive Status Review” of V. utahensis back in 2007:
More Snake River Gastropods Studied for Delisting (14June07)

(2) U.S. Fish and Wildlife Service finds Utah (Desert) Valvata Snail No Longer Needs Protection [PDF]

(3) Endangered and threatened wildlife and plants; Determination of endangered or threatened status for five aquatic snails in south central Idaho. Federal Register 57(240): 59244-57. (December 14, 1992) [PDF]

(4) Endangered and threatened wildlife and plants; Removal of the Utah (Desert) Valvata snail from the federal list of endangered and threatened wildlife. Federal Register 75(164): 52272-82. (August 25, 2010) [PDF]

(5) I posted four essays on the Snake River Pyrgulopsis controversy as it unfolded:
Idaho Springsnail Showdown (28Apr05)
Idaho Springsnail Panel Report (23Dec05)
When Pigs Fly in Idaho (30Jan06)
FWS Finding on the Idaho Springsnail (4Oct06)

(6) Call, R. E. (1884) On the Quaternary and recent Mollusca of the Great Basin, with descriptions of new forms. U.S. Geol. Survey Bulletin 11: 1-64.

(7) Walker, B. (1902) A revision of the carinate valvatas of the United States. Nautilus 15; 121-125.

(8) See my 2008 review of the “Snake River Physa” controversy in:
Red flags, water resources, and Physa natricina (14Mar08)

(9) See the main FWS page for the Snake River Physa [html]

(10) Actually, there’s a flowchart outlining the process in a document entitled “Delisting a Species” available from the Idaho FWS website. [PDF]

(11) The FWS announced a five year review of T. serpenticola (the “Bliss Rapids Snail”) in July 2004, but ultimately decided to preserve its threatened status:
Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to Remove the Bliss Rapids Snail (Taylorconcha serpenticola) From the List of Endangered and Threatened Wildlife. Federal Register 74(178): 47536-45. (Sept. 16, 2009) [html]

(12) I’m being charitable here. There is some real possibility that the interests spearheading the 1992 listing process were not innocent naïfs, but cynically manipulating the endangered species act for politics and profit. The essay of [14Mar08] referenced in note (8) above was written in one of my less-charitable moods.