> Habitat & Distribution

This is another of three nominal species of hydrobiid gastropods endemic (or nearly endemic) to springs and spring-fed tribuarties of the Ocmulgee River in the vicinity of Hawkinsville, Georgia.  Like Notogillia sathon, The FLMNH also holds a few collections of S. turgida from tributaries of the Oconee River in Laurens County, GA.  Watson (2000) characterized the habitat of both Spilochlamys and Notogilla as "relatively undisturbed pools of springs or small streams," with substrate "mud-silt-sand mixture, sometimes with leaf litter and woody debris."  Spilochlamys turgida demonstrates non-apparent rarity in our 17-state study area, FWGNA incidence rank I-3*.

> Ecology & Life History

Hydrobiids seem to be rather nonspecific grazers of small particles (Dillon 2000: 94-97).  They are typically dioecious, the males being characterized by a penis that arises from the neck.  Females attach single eggs in spare, hemispherical capsules to solid substrates (Hershler 1994).  No specific life history data are as yet available for S. turgida.

> Taxonomy & Systematics

Like Marstonia, Notogillia, and Floridobia, the genus Spilochlamys belongs to the subfamily Nymphophilinae of the family Hydrobiidae (ss), males being characterized by a lobe-shaped penis (or verge) with surficial glandular patterns (Kabat and Hershler 1993, Hershler et al. 2003, Thompson 2004).  The penis of S. turgida has been figured by Thompson (1969).

This penial morphology, together with a relatively large shell, bearing a depressed apex and squarish shoulders, makes S. turgida distinct from any other hydrobiid of U.S. Atlantic drainages.  There are two other species of Spilochlamys in Florida, bearing slightly different arrangements of penial glands and somewhat higher spires (Thompson 1968).

> Supplementary Resources [PDF]

• Spilochlamys distribution in Atlantic drainages (2013)   

> Essays

• Conservation-biased oversampling of Spilochlamys turgida was featured in my blog post of 19Mar12, "Toward the Scientific Ranking of Conservation Status - Part III."
• 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.

> References

Dillon, R. T., Jr. (2000)  The Ecology of Freshwater Molluscs. Cambridge, Cambridge University Press.  509 pp
Hershler, R. (1994)  A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae). Smithsonian Contributions to Zoology 554:1-115.   
Hershler, R., H. Liu, and F.G. Thompson (2003)  Phylogenetic relationships of North American nymphophiline gastropods based on mitochondrial DNA sequences.  Zoologica Scripta 32:357-366.   
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.   
Thompson, F.G. (1968)  The Aquatic Snails of the Family Hydrobiidae of Peninsular Florida. University of Florida Press, Gainesville, Florida, USA.   
Thompson, F.G. (1969) Some hydrobiid snails from Georgia and Florida. Quarterly Journal of the Florida Academy of Sciences 32:241-265.  
Thompson, F.G. (2004) An identification manual for the freshwater snails of Florida.   
Thompson, F. G. & R. Hershler (2002)  Two genera of North American freshwater snails: Marstonia Baker, 1926, resurrected to generic status, and Floridobia, new genus (Prosobranchia: Hydrobiidae: Nymphophilinae).  The Veliger 45: 269 - 271.
Watson, C. N.  (2000)  Results of a survey for selected species of Hydrobiidae (Gastropoda) in Georgia and Florida.  pp. 233 - 244 in Freshwater Mollusk Symposium Proceedings (Tankersley et al, eds)  Ohio Biological Survey, Columbus. 
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.