FWGNA > Species Accounts > Pleuroceridae > Leptoxis praerosa
Leptoxis praerosa (Say 1821)
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> 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." Our modern surveys have confirmed scattered populations of L. praerosa in the main Ohio River and major tributaries such as the Licking, the Green, and the Wabash.  We have only a single record from any Cumberland drainage - the Harpeth - suggesting that Goodrich may have confounded L. praerosa with L. umbilicata further upstream. 

Populations are, however, very common and widespread throughout the major tributaries of the Tennessee River (although not in the main Tennessee itself) from the main stems of the Powell, Clinch, and Holston Rivers of southwest Virginia through the Elk R. and Duck R. of Middle Tennessee, including Northern Alabama and a corner of North Georgia.  A population of L. praerosa seems to have spread into the New/Kanawha drainage, occurring sympatrically with L. carinata in Walker Creek and upper Wolf Creek in Giles and Bland Counties, Virginia.  We are also aware of a couple L. praerosa populations in western North Carolina, inhabiting tributaries of the Hiwassee (Dillon 1992).  FWGNA incidence rank I-5.

Throughout this extensive range, L. praerosa seems to reach maximum population densities in medium-sized rivers, on rocks in riffles with good flow.  Populations are not commonly encountered in small creeks or streams, nor in larger rivers where substrates become too silty.

> 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).

Like other pleurocerids, L. praerosa is dioecious, eggs being deposited on hard substrates from spring to mid-summer.  Whelan and colleagues (2015) described eggs as being laid "singly in an apparently random manner" under their culture conditions.  Although we are unaware of any study specifically directed toward the life history of L. praerosa, it seems reasonable to expect that two years will be required for maturity, and that several years of iteroparous reproduction can be expected thereafter, as is the case for pleurocerids generally (Dazo 1965). This is life cycle Hi of Dillon (2000: 156 - 162).

> 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), and for the mtDNA sequence study of Whelan & Strong (2016).  See my essay of 3Apr16 for more.  "Anculosa" is a commonly-encountered synonym for the genus, and subglobosa a common synonym for the species.

> Supplementary Resources

  • Pretty photo of living Leptoxis praerosa, courtesy of Chris Lukhaup.Click for larger image

> Essays

  • Although focused on the pleurocerid fauna of the Mobile Basin, the genetic survey of Whelan & Strong (2016) also included mtDNA sequence data from a North Alabama population of L. praerosa as an outgroup control.  Their results were reviewed in my essay of 3May16, Mitochondrial Superheterogeneity and Speciation.

> References

Dazo, B. C. 1965. The morphology and natural history of Pleurocera acuta and Goniobasis livescens (Gastropoda: Cerithiacea: Pleuroceridae). Malacologia 3: 1 - 80. 
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.

Jokinen, E.H. 1992. The Freshwater Snails (Mollusca: Gastropoda) of New York State. NY State Mus Bull 482, Albany, New York. 
Smith, D.G. 1980. Goniobasis virginica Gastropoda Pleuroceridae in the Connecticut River USA. Nautilus 94:50-54.
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.
Whelan, N. V., P.D. Johnson & P. M. Harris (2015)  Life-history traits and shell morphology in the genus Leptoxis Rafinesque, 1819.  J. Moll. Stud. 81: 85-95.
Whelan, N.V. & E. E. Strong (2016)  Morphology, molecules and taxonomy: extreme incongruence in pleurocerids (Gastropoda, Cerithiodea, Pleuroceridae). Zoologica Scripta 45: 62 – 87.