Editor’s Note – This essay was subsequently published as: Dillon, R.T., Jr. (2023b) Finding Fontigens cryptica. Pp 211 – 215 in The Freshwater Gastropods of North America Volume 6, Yankees at The Gap, and Other Essays. FWGNA Project, Charleston, SC.
Faithful readers of this blog may remember a series of
essays I posted back in 2017 about Lori Schroeder’s tiny snail, the obscure
hydrobiid Fontigens cryptica [1]. The
species was described in 1963 by Hubricht [2] from a spring in southern Indiana
about the size of a man’s fist, and has not been seen at its type locality
since, despite repeated efforts to recollect it. The only subsequent live collections have
been made by J. J. (Jerry) Lewis, extracted from subterranean stream gravels at
a couple widely-scattered sites in Indiana.
Our buddy Jerry has suggested that F. cryptica may be obligately adapted
to the interstitial spaces of aquifers.
So back in 2008 Mrs. Lori Schroeder, a talented amateur
malacologist living in central Kentucky, enlisted in a Bioblitz one-year survey
of the land snail fauna of the nearby Bernheim Arboretum and Research
Forest. And in addition to her land
snails, in 2013 she began to run across scattered, rare hydrobiid shells in dry
forest litter sampled alongside several small Bernheim streams, which she and I
were ultimately able to identify as those of Fontigens cryptica. But despite long term, persistent, and heroic
efforts on her part she had not, as of 2017, been able to discover a single
living individual. As I brought my
series of essays to a close, I mentioned something about Lori’s plans for a
Bou-Rouch groundwater sampler and promised to keep you all posted.
 |
| Lori Schroeder's tiny snail |
A Bou-Rouch sampler is basically a hand-powered piston pump
with a short intake, modified to be driven into the ground [3]. Lori and her husband Jeff did all manner of
impressive research on soil types, subterranean gravels and impervious layers
in the Bernheim area, purchased the necessary hardware, assembled the machine,
and by the 2018 season were hard at work pumping groundwater through lady’s
trouser socks ($1.00/2pk from Dollar General).
They extended their search into neighboring, privately-held tracts,
exploring new springs, old wells, and small caves. And finished the 2018 field season in
failure. Lori did not give up hope, but
she did need some sort of new idea.
Meanwhile her land snail survey continued. And a couple months ago I got an excited
email from her, reporting the discovery of another dry Fontigens shell in a
previously unexplored valley recently added to the Bernheim management
portfolio – the Cedar Grove Tract, about 15 km north of the Harrison and Wilson
Creek areas where she had been concentrating her efforts. And the Cedar Creek drainage boasts a spring
that Lori characterized as “super nice” with “ice cold crystal clear water.”
 |
| The super-nice spring |
So, on Friday morning, 24May19, a Corps of Discovery
comprised of Lori, Jeff, and Bernheim Director of Conservation Mr. Andrew Berry
launched an expedition to the upper regions of the Cedar Grove Tract. This was my benediction, verbatim: “find a
decent-sized rock, or rocks, DIRECTLY at the spring head. Right where the water comes out of the
ground. Pick up that rock and look attached
UNDERNEATH it. That’s where your
Fontigens will be.”
And the next day, Lori sent me glad tidings that their expedition had been crowned with success! The photo above shows a rock ledge running to
the right of the super-nice spring, as the photographer is standing in the
spring run. Under that ledge was a
decent-sized rock, and attached to the underside of that decent-sized rock was
one, single Fontigens cryptica. The
snail was translucent, whitish, and blind, as originally described by Hubricht
in 1963. Next time bring forceps.
Clearly the genetics of one single little white snail found under a rock at a springhead in central Kentucky cannot be studied in isolation. The significance of Lori Schroeder’s tiny snail can only be understood contextualized by at least a rudimentary understanding of the evolution of the North American Fontigens as a group.
Phylogenetically, the group is among the most difficult to place of all the North
American hydrobioid gastropods. They
share their strange, multiply-lobed penial morphology only with the Old World
genus Emmericia, which prompted Morrison [4] to assign the genus to the
subfamily Emmericiinae in the old Hydrobiidae (s.l.), a judgement subsequently
endorsed by Hershler [5]. Dwight Taylor
[6] disagreed, proposing a new subfamily Fontigentinae to contain them, a
judgement endorsed by Burch [7]. The new
classification system recently proposed by Wilke and colleagues [8] split out a
separate Emmericiidae while retaining Fontigens in the Hydrobiidae (s.s.) on
the basis of DNA sequence data from a single individual Fontigens nickliniana
sampled from Michigan in 2012. To this
day, the CO1 and 18S sequences from that single F. nickliniana remain the only
Fontigens data deposited in GenBank.
 |
| From left: Andrew Berry, Fontigens cryptica, Lori Schroeder |
So, I called our colleague Hsiu-Ping Liu at the University
of Denver. And it materialized that she
was very much interested in the evolution of Fontigens, and that Bob Hershler
had sent her a not-insubstantial collection of samples prior to his retirement
last year. And I myself am currently
holding a nice collection of cave snail samples that our good friend Wil
Orndorff sent me last year from the long term VA-DCR biotic survey of Virginia
caves [9]. And together Hsiu-Ping and I
worked up a small proposal to the Bernheim Board for a study on the evolution
of Fontigens across the eastern USA.
Meanwhile Lori and Andrew have mounted several additional
field trips to the Cedar Creek Spring and failed to find any additional
snails. We’ll keep you posted on
progress along both fronts.
Let me leave you this month with three teasers, and a
reading assignment:
- If you were a state consultant looking for a broad strip of open land to connect Interstate 65 and Interstate 71 around greater metropolitan Louisville, where might you find it?
- If you were a planner with Louisville Gas & Electric, looking for an open corridor through which to run a natural gas pipeline, where might you run it?
- How much noise can one tiny white snail make?
Notes
[1] These three essays were published earlier this year on
pp 235 - 250 of my new book, The Freshwater Gastropods of North America, Volume
III: Essays on the Prosobranchs [html].
To refresh your memory:
- Lori Schroeder’s Tiny Snails [17July17]
- The Most Cryptic Freshwater Gastropod in The World [6Aug17]
- Not Finding Fontigens cryptica [6Sept17]
[3] More about the Bou-Rouch method is available at the
website of the Hypogean Crustacea Recording Scheme [html]
[4] Morrison, J. P.
E. (1949) The Cave Snails of Eastern
North America (abstract). The American
Malacological Union Bulletin 15: 13 – 15.
[5] Hershler, R., J. R. Holsinger and L. Hubricht
(1990) A revision of the North American
freshwater snail genus Fontigens (Prosobranchia: Hydrobiidae). Smithsonian Contributions to Zoology 509: 1 –
49.
[6] Taylor, D. W. (1966)
A remarkable snail fauna from Coahuila, Mexico. Veliger 9: 152-228.
[7] Burch originally
proposed his classification for the North American freshwater gastropods in
1978 (Journal de Conchyliologie 115: 1-9). His "North American Freshwater
Snails" was published as an EPA manual in 1982, as three volumes of
Walkerana (1980, 1982, 1988), and as a stand-alone book in 1989.
[8] 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:
- The Classification of the Hydrobioids [18Aug16]
- Cave Snail Adventure [22Aug07]