Horton hears two new species of Fontigens

Wanted: Collaborator.  Washed-up malacologist tragically enthralled by The Modern Synthesis of Darwin + Mendel seeks bright young evolutionary biologist with good molecular skills and the patience to (1) slog through last month’s discursive essay, (2) wade through this month’s ridiculous essay as well, and (3) write a grant proposal accordingly.  Apply within.

Last month [12Feb26] we refreshed our collective memory on the seven species of the hydrobioid genus Fontigens that were known, at the close of the twentieth century, to inhabit caves, springs, and spring runs in the Great Valley of Virginia [1], including one that isn’t a Fontigens but should be [2], and one that hasn’t been confirmed from the Great Valley but could be.

F. malabadi, Repass Saltpetre Cave

And we reviewed the mighty works of our heroes, Wil Orndorff and Tom Malabad of the VaDCR, collecting 87 samples of tiny gastropods from caves and springs in The Great Valley 2013 – 2019 [3] and delivering them in good order to my Charleston doorstep in three batches 2018 - 2020.  Five of those samples, collected from caves in Scott and Giles Counties, contained Fontigens that were unique to my eyes, which I dissected, described, and forwarded onward to our colleague Hsiu-Ping Liu in Colorado for sequencing.  Our description of three new species was published in 2023 [4], bringing the Valley total fauna of phreatic hydrobioids up to ten.

What I did not mention last month is that one single sample, collected from Repass Saltpetre Cave in Bland County in 2019, was of a population of Fontigens bearing shells unique to my eyes, that I forwarded on to Hsiu-Ping for sequencing, from which she was unable to amplify any DNA.  Disappointed, I settled for an identification of Fontigens-orolibas-question-mark and dropped it.

And what I concluded last month’s essay with was a teaser, strongly implying that we had not heard the last of Tom Malabad and Wil Orndorff.  For their explorations of the caves, karst features, springs and spring runs of the Great Valley of Virginia have continued, even unto the present day.  And on September 24, 2024, another big batch of 52 tiny vials, each containing even bigger batches of even tinier snails, floated down upon my Charleston doorstep light as Horton’s speck.

That batch of 52 samples, collected 2020 – 2025, contained 19 vials of snails that my daddy would have dismissed as “no count” – land snails, freshwater gastropods more common in above-ground waters, and one Fontigens too busted up to identify.  Then in the 33 samples of consequence, I identified 35 populations of phreatic gastropods: 10 Fontigens orolibas, 4 F. nickliniana, 4 F. bottimeri, 3 F. morrisoni, 3 Holsingeria, 2 F. tartarea, 1 F. hershleri [5], and 8 populations of Fontigens bearing shells unlike any I had ever seen before. Almost.

Now to be quite precise.  Among those 52 samples were a pair of fresh samples, one collected in 2022 and another in 2024, from that same peculiar population inhabiting the waters of Repass Saltpetre Cave in Bland County I had flagged several years previous.  The shells borne by the Fontigens in that pair of samples reinforced the impression of uniqueness that had first struck me in the 2019 sample, characterized by tighter whorls, a smaller body whorl, and a higher spire than any Fontigens previously described.  See the figure up at the top of this essay.

Gallohan Cave #1

And also among the 52 vials that arrived on my doorstep in September were a pair of samples collected 22Jan25 and 5Aug25 from The Caverns at Natural Bridge Villa in Rockbridge County, bearing shells that matched the Repass Saltpetre population. And good grief!  In a third vial, collected in 2021 from Gallohan Cave #1 way down at the tip of Virginia in Lee County, I found a mixture of 5 Holsingeria and 2 Fontigens (red arrows above) bearing that same, peculiar Repass Saltpetre shell morphology.

Here I describe a new species, Fontigens malabadi Dillon MS, in honor of my esteemed colleague Thomas E. Malabad.  The shell of Fontigens malabadi is distinguishable from that of all previously-described species in the genus by relatively tight, rounded whorls, a small body whorl, and a high spire.  The type locality is a stream in Repass Saltpetre Cave, Bland County, Virginia.  Other populations of F. malabadi are known from cave streams in Rockbridge County and Lee County, Virginia.

F. orndorffi, Kinzer Hollow Cave

But wait, there’s more.  Also among the 52 vials delivered to my Charleston address in September were three samples of Fontigens bearing shells really, seriously unlike anything I had ever seen before, not just in the published literature but in all 87 samples collected by Wil & Tom 2013 – 2019.  These were collected from Spangler Cave and Kinzer Hollow Cave way down south in Lee County, and in Rogers Belmont Cave way up north in Warren County, Va.  That last sample, just a single individual actually (red arrow below), was mixed with two individual Fontigens orolibas.

Here I describe a second new species, Fontigens orndorffi Dillon MS, in honor of my esteemed colleague William D. Orndorff.  The shell of Fontigens orndorffi is distinguishable from that of all previously-described species in the genus by relatively tight, flat-sided whorls, a small body whorl, and a high spire.  The type locality is a stream in Kinzer Hollow Cave in Lee County, Virginia.  Other populations of F. orndorffi are known from streams in Spangler Cave (Lee County) and Kinzer Hollow Cave (Warren County).

Rogers Belmont Cave

These are but manuscript descriptions at present.  As I noted in last month’s essay, in this day and age it is irresponsible to formally describe a new species without genetic confirmation of some sort.  And I have none.

But let me stop right here, back out of my disorderly narrative, and try to cast a broad perspective over the entire inventory of 87 + 52 = 139 samples of tiny snails stacked at the end of my lab bench this afternoon, and all six essays I have posted on this subject thus far, 2006 - 2026 [6].  There has been an endemic radiation of Fontigentid gastropods in The Great Valley of Virginia.  And several generations of malacologists, including my own, have been Humpfing around the edges of it for years, like sour kangaroos.  

Sure, I’d be pleased to find a collaborator to sequence a couple genes on a few snails and help me with the descriptions of Fontigens malabadi and F. orndorffi, no matter how small.  But what we really need is a PI to write a big grant proposal to take all 139 little vials off the end of my lab bench and see if we can work out the fascinating history of the entire evolutionary radiation.

Because the joint distribution of these 12+ enigmatic little creatures is a codex of the Appalachian orogeny.  Exactly like the pleurocerid snails, their distributions are older – much older – than the drainage basins in which they live.  Populations of Fontigens do not give a rat’s rear end whether their cave stream is running toward the Atlantic, the Ohio, or the Tennessee.  Even modern crow-fly distance means nothing to them.  Let me give you just one example.

The Great Valley of Virginia

Bob Hershler described Holsingeria unthanksensis – certainly the most peculiar element of the fauna – as endemic to Unthanks Cave in Lee County, draining toward the Tennessee River way down in the SW tip of Virginia [2].  Since 1989, Holsingeria populations have been discovered in four other Lee County caves (Spangler, Tater, Burial, and Gibson #1).  Then in 2003, Hershler and colleagues documented a highly disjunct population of Holsingeria in Skyline Caverns, way up north in Warren County, draining through the Shenandoah River to the Atlantic [7].  And no populations of Holsingeria have ever been discovered in the 500 linear kilometers between Lee and Warren County whatsoever.

Now here in the present essay I have described a new species, Fontigens orndorffi, with exactly that same bizarre distribution.  Fontigens orndorffi co-occurs with Holsingeria in Spangler Cave, way down in Lee County, as well as in Kinzer Hollow Cave, a few km E of Spangler.  And F. orndorffi is also found in Warren County, in Rogers Belmont Cave just a couple km W of Skyline Caverns.  And no populations of F. orndorffi are known in the 500 km between Lee and Warren Counties, either.

That is not a coincidence.  These tiny snails are trying to tell us something big about the ancient history of the Southern Appalachians.  If you hear that Yopp as clearly as I do, and you want to help, apply within.

Notes:

[1] Hershler, R., J.R. Holsinger & L. Hubricht (1990) A revision of the North American freshwater snail genus Fontigens (Prosobranchia: Hydrobiidae). Smithsonian Contributions to Zoology 509: 1-49.  For a review and an appreciation, see:

• Springsnails of the Blue Ridge [26July06]
• My Buddy Bob [6July22]

[2] Hershler, R. H. (1989) Holsingeria unthanksensis, a new genus and species of aquatic cavesnail from eastern North America. Malac. Rev. 21: 93-100.  For more, see:

• Cave Snail Adventure [22Aug07]

[3] Actually one sample from 1987 and one from 2008.  But the rest from 2013 – 2019.

[4] Dillon, R.T., Jr., T.E. Malabad, W.D. Orndorff & H-P. Liu (2023) Three new Fontigens (Caenogastropoda: Fontigentidae) from caves in the Appalachian Ridge and Valley Province, Virginia. Pp. 283 - 306 in Dillon, R.T., Jr. et al. The Freshwater Gastropods of North America Volume V: Ohio, Cumberland, and Tennessee River Systems. FWGNA Press, Charleston. [pdf]  For a review, see:

• Three New Fontigens from Virginia [9Jan24]

[5] This is just the second population of F. hersheri ever discovered: Litton Cave #1, Lee County.

[6] In addition to my essays of 26July06, 22Aug07 and 9Jan24 linked above, one must count last month's essay (12Feb26), this month's essay (5Mar26) and my review of the 2021 molecular study published by Liu, Schroeder, Berry, and Dillon [pdf]:

• Startled by Fontigens, sort-of, I suppose [9Aug22]

[7] Hershler, R. H., H-P. Liu & F. G. Thompson (2003) Phylogenetic relationships of North American nymphophiline gastropods based on mitochondrial DNA sequences. Zoologica Scripta 32: 357-366.