Sphalloplana subtilis Kenk, 1977
Bigger's groundwater planarian
Taxonomy & Nomenclature
Conservation Status
Missing (Culver et al., 2012)
Last record: 12 August 1973 (Kenk, 1977:13)
The spring was on the property of Mr. J. W. Biggers, and was enclosed by a brick dome and concrete cap, by the time it was first sampled for wildlife in the early 1970's (Kenk, 1977; Culver et al., 2012). Three taxa were recorded: two planarians (S. holsingeri and S. subtilis) and an amphipod (Stygobromus tenuis potomacus). While the amphipod has been recorded more widely, the two planarians of the genus Sphalloplana were endemic to this single spring as far as anyone knows. Both were last recorded on 12 August 1973 (Kenk, 1977), and the spring has since been destroyed and built over (Culver et al., 2012).
Distribution & Habitat
Fairfax County, Virginia, USA (Culver et al., 2012)
Type locality: "a spring on the property of J. W. Biggers at 6278 East Edsall Road, Fairfax County, Virginia, close to the Alexandria city line" (Kenk, 1977:13) / "shallow well (Biggers Spring) on Edsall Road, Fairfax County, VA [now destroyed]" (Culver et al., 2012)
Biology & Ecology
Hypodigm
Media
References
Original scientific description:
Kenk, R. (1977). Freshwater Triclads (Turbellaria) of North America, IX: The Genus Sphalloplana. Smithsonian Contributions to Zoology, Number 246. Smithsonian Institution Press, Washington, D.C. 38 pp. http://dx.doi.org/10.5479/si.00810282.246
Other references:
Carpenter, Jerry H. (1982). Observations on the Biology of Cave Planarians of the United States. Int. J. Speleol. 12: 9-26.
Culver, David C., Holsinger, John R. and Feller, Daniel J. (2012). The fauna of seepage springs and other shallow subterranean habitats in the mid-Atlantic piedmont and coastal Plain. Northeastern Naturalist 19(mo9): 1-42. https://doi.org/10.1656/045.019.m901
Kenk, R. (1989). Revised list of the North American freshwater planarians (Platyhelminthes: Tricladida: Paludicola). Smithsonian Contributions to Zoology 476: 1-20.
NatureServe. (2025). Sphalloplana subtilis: Bigger's Groundwater Planarian. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available at: https://explorer.natureserve.org/ [Accessed 1 June 2025]
Roble, S. M. (2016). Natural Heritage Resources of Virginia: Rare Animals. Natural Heritage Technical Report 16-07. Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, Virginia. 56 pp.
Tyler, S., Artois, T., Schilling, S., Hooge, M. and Bush, L. F. (eds.). (2006-2025). World List of turbellarian worms: Acoelomorpha, Catenulida, Rhabditophora. Sphalloplana (Sphalloplana) subtilis Kenk, 1977. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=482005 on 2025-06-01