> Leptoxis praerosa (Say 1821)
  

> Habitat & Distribution
The range of L. praerosa was given by Goodrich (1940) as "Ohio River below Cincinnati to Elizabethtown, Illinois, together with a few tributaries; Cumberland River and branches; Duck River, Coffee County, Tennessee to mouth; Tennessee River, and lower parts of tributaries."  The species is very common in the main stems of the Powell, Clinch, and Holston Rivers of southwest Virginia, as well as their larger tributaries, on rocks in riffles with good flow.  It also seems to have spread into the New/Kanawha drainage, occurring sympatrically with L. dilatata in Walker Creek and upper Wolf Creek in Giles and Bland Counties, Virginia.  We are aware of one population of L. praerosa in western North Carolina, inhabiting the Valley River, a tributary of the Hiwassee (Dillon 1992).

> Ecology & Life history
Grazing by populations of pleurocerids can have a significant effect on energy flow in small streams (Dillon 2000: 86 - 91, see also Dillon & Davis 1991).  

> Taxonomy & Systematics
This is a widespread and well-characterized species.  Several populations of L. praerosa from central and southern Tennessee served as controls for the allozyme surveys of Dillon & Ahlstedt (1997) and Dillon & Lydeard (1998).  "Anculosa" is a commonly-encountered synonym for the genus. 

>Pretty photo
Living L. praerosa, courtesy of Chris Lukhaup.

 
>References
Dillon, R. T., Jr. (1989)  Karyotypic evolution in pleurocerid snails: I. Genomic DNA estimated by flow cytometry. Malacologia, 31: 197-203.  Dillon, R. T., Jr. (1992)  Status survey of the knotty elimia, Goniobasis interrupta (Hald).  Report to the North Carolina Wildlife Resources Commission, Contract 92-Snai-01.  19 pp.  Dillon, R. T., Jr. (2000)  The Ecology of Freshwater Molluscs. Cambridge, Cambridge University Press.  509 pp.  Dillon, R. T., Jr. & S. A. Ahlstedt (1997)  Verification of the specific status of the endangered Anthony's River Snail, Athearnia anthonyi, using allozyme electrophoresis.  Nautilus 110: 97-101.  Dillon, R. T. Jr., & K. B. Davis (1991)  The diatoms ingested by freshwater snails: temporal, spatial, and interspecific variation. Hydrobiologia 210: 233-242.  Dillon, R. T., Jr., and C. Lydeard (1998)  Divergence among Mobile Basin populations of the pleurocrid snail genus, Leptoxis, estimated by allozyme electrophoresis.  Malacologia 39: 113-121.  Goodrich, C. (1940) The Pleuroceridae of the Ohio River drainage system.  Occas. Pprs. Mus. Zool. Univ. Mich., 417: 1-21.  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.