Dr. Rob Dillon, Coordinator





Wednesday, July 3, 2019

Finding Fontigens cryptica


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.

Lori Schroeder's tiny snail
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.

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 their efforts were 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.

The genus Fontigens is among the poorest-known of 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
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.

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?
Now study this press release:
  • New rare snail discovered on proposed pipeline, interstate connector routes [html] [pdf]
To be continued!


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]
[2] Hubricht, L. (1963)  New species of Hydrobiidae.  Nautilus 76: 138 - 140.

[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]
[9] We first met Wil Orndorff in my essay about an expedition for Holsingeria unthanksensis in southwest Virginia.  See pp 217 - 222 in The Freshwater Gastropods of North America, Volume III: Essays on the Prosobranchs [html].  Or: