> Habitat & Distribution

Populations identified as Fontigens orndorffi have been discovered in a pair of caves in Lee County, Va, with entrances about 4 km apart: Spangler Cave and Kinzer Hollow Cave.  A third, highly disjunct population seems to inhabit Rogers Belmont Cave in Warren County, approximately 500 km north.  The Lee County populations inhabit a cave stream draining south through the Powell River to the Tennessee; the Warren County population inhabits a stream draining north through the Shenandoah River to the Atlantic.  Little hydrobioid cave snails such as these are typically found grazing on and under cobbles.

A broad-brush review of the zoogeography of North American cavesnails has been offered by Hershler & Holsinger (1990), and a more detailed review for the genus Fontigens by Gladstone and colleagues (2021). FWGNA incidence unranked.

> Ecology & Life History

The waters inhabited by stygobiontic Fontigens such as F. orndorffi are characterized by nearly-constant temperatures year around, richness in minerals, and poverty in organics. Presumably their entire ecosystem is based on fine organic matter raining down from the lighted world above.above.

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

Fontigens orndorffi has not been formally described.  Quoting the manuscript description, which we published in blog form on [date], the shell “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.”  No anatomical observations or genetic data are as yet available.

The first populations of Fontigens orndorffi and F. malabadi came to light in a large sample of phreatic gastropods collected from caves, springs, and spring runs in the Great Valley of Virginia by VaDCR biologists 2018 – 2025.  If confirmed, they would count as species #11 and #12 in an endemic radiation that has gradually come to the attention of the malacological community over a period of about 40 years now.  See my essays of DATE and DATE from the links below for a complete review.

Taylor (1966) suggested that Fontigens comprised 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.

> Supplementary Resources

• Maps of Fontigens distribution.
  

> 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 among Fontigens populations sampled across eastern North America.
• Posted a broad review called An endemic radiation, no matter how small on DATE. Features photos comparing the shell morphology of all ten Fontigens species known as of 2023.
• Followed up with Horton hears two new species.

> 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.
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]
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. H. & J. R. Holsinger (1990) Zoogeography of North American hydrobiid cavesnails. Stygologia 5: 5-16.
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.
Taylor, D.W. (1966) Summary of North American Blancan nonmarine molluscs. Malacologia 4: 1 - 172.
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.