> Habitat & Distribution

Hershler and his colleagues (1990) gave the distribution of F. bottimeri as "a few localities in Potomac River basin of District of Columbia and Maryland, and Shenandoah River basin of northwestern Virginia.  Found in both caves and small springs."  The only Virginia population documented by Hershler was that of Ogden's Cave in Frederick County.  We are aware of one additional Virginia population, in a small spring run on private property in Frederick county. The USNM also currently holds about 15 records from western Maryland, including several from tributaries of the Youghiogheny, draining NW into The Ohio.  See the paper by Gladstone et al. (2021) for a more complete review of the distribution of Fontigens bottimeri.  FWGNA incidence rank I-3*, non-apparently rare.

> Ecology & Life History

I am not aware of any study on the life history of Fontigens bottimeri.  But populations typically seem to maintain high densities year round, as though reproduction might be continuous.  The small spring run inhabited by our Virginia F. bottimeri population seemed rather rich and hard.

Weck (2022) reported approximately one year to maturity (3 mm) in laboratory populations of the cave-dwelling Fontigens antroecetes, constant low levels of reproduction (25 - 80 eggs/pair/yr), and a lengthy hatch time of 70 - 80 days.

> Taxonomy & Systematics

The penial morphology of F. bottimeri may be distinguished from that of all other eastern species by the presence of three accessory lobes, rather than two.  The multivariate study of Gladstone et al. (2021) suggested (on small sample size) that the shell morphology of F. bottimeri is distinct from eight other recognized species studied.

The mtDNA sequence study of Liu and colleagues (2021), across 13 populations of 9 Fontigens species, included samples from two F. bottimeri populations: one in Virginia and a second in Washington, DC.  See my essay of 9Aug22 from the link below for a review.

Taylor (1966) suggested that Fontigens comprises a distinct hydrobiid subfamily, the Fontigentinae, which Hershler et al. (1990) synonymized under the Emmericiinae of Brusina (1870).  Wilke et al. (2013) did not confirm a close association between Fontigens (represented by a single sample) and the European genus Emmericia, however, tentatively returning the Fontigentinae to subfamilial status.  Despite this evidence, self-appointed experts insisted on placing Fontigens in the Emmericiidae for several years (Bouchet et al. 2017), until Gladstone & Whelan (2022) split the genus to its own separate family, the Fontigentidae.

> Maps and Supplementary Resources

• Fontigens distribution in Atlantic drainages (2023)
• Fontigens distribution in drainages of The Ohio (2019)
• Virginia species account with county distribution (2011)

> Essays

• Earlier versions of this website, online until August of 2016, adopted the large, broadly-inclusive concept of the Hydrobiidae (sl) following Kabat & Hershler (1993).  More recently the FWGNA project has shifted to the Wilke et al. (2013) classification system, distinguishing a much smaller Hydrobiidae (ss) and elevating many hydrobioid taxa previously ranked as subfamilies to the full family level.  For more details, see The Classification of the Hydrobioids.
• See my essay of 9Aug22, Startled by Fontigens, sort-of, I suppose for a review of the paper by Liu et al. (2021) documenting unusually high levels of intraspecific mtDNA sequence divergence in F. bottimeri.

> References

Bouchet, P., J. Rocroi, B. Hausdorf, A. Kaim, Y. Kano, A. Nutzel, P. Parkhaev, M. Schrodl, and E. Strong (2017) Revised classification, nomenclator and typification of gastropod and monoplacophoran families. Malacologia, 61: 1–526.
Gladstone, N.S., E. Pieper, S. Keenan, A. Paterson, M. Slay, K. Dooley, A. Engel, and M. Niemiller (2021)  Discovery of the Blue Ridge springsnail, Fontigens orolibas Hubricht 1957 (Gastropoda: Emmericiidae) in East Tennessee and its conservation implications.  Freshwater Mollusk Biology and Conservation 24: 34 - 42.
Gladstone, N. S. and N. Whelan (2022) Pushing barcodes to their limits: phylogenetic placeament of Fontigens Pilsbry, 1933 (Caenogasatropoda: Littorinimorpha: Truncatelloidea) and elevation of Fontigentidae Taylor, 1966.  Journal of Molluscan Studies 88: eyab038.
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.
Kabat, A.R., and R. Hershler (1993) The prosobranch snail family Hydrobiidae (Gastropoda: Rissooidea): review of classification and supraspecific taxa. Smithsonian Contributions to Zoology 547:1-94.
Liu, H-P., L. Schroeder, A. Berry, and R. T. Dillon, Jr. (2021)  High levels of mitochondrial DNA sequence divergence among isolated populations of Fontigens (Truncatelloidea: Emmericiidae) in eastern USA.  Journal of Molluscan Studies 87:  eyab026. [pdf]
Stewart, T. W., & R. T. Dillon, Jr.  (2004)  Species composition and geographic distribution of Virginia's freshwater gastropod fauna: A review using historical records.  Am. Malac. Bull. 19: 79-91.
Taylor, D.W. (1966) Summary of North American Blancan nonmarine molluscs.   Malacologia  4: 1 - 172.
Walker, B.  (1925)  New species of freshwater operculates. Nautilus 39: 5 - 8.
Weck, R.G. (2022)  Life history observations of the Illinois state endangered Enigmatic Cavesnail, Fontigens antroecetes (Hubricht, 1940) made under simulated cave conditions.  Subterranean Biology 43: 185 - 198. 
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.