>Lioplax subcarinata (Say 1817)

> Habitat & Distribution
Burch (citing Clench & Turner 1955, Clench 1965, and Vail 1979) gave the range of L. subcarinata as the Hudson River drainage south to South Carolina. But Jokinen (1992) reported the species extirpated from New York, and for years I was unable to confirm the occurrence of Lioplax at the southern limit of its range as well. The essay I posted in 2004 reporting the rediscovery of the species in the Lynches River near Bishopville is reachable from the link below. The animals seemed fairly common in the summer of 2004, burrowing in extremely flocculent silt.  I have subsequently collected Lioplax downstream as far as Lynches Mill in Florence County.

In 2005 my attention was called to a second South Carolina population, this in the Waccamaw River at Peachtree Landing, Horry County (Tim Savidge).  And the species is not uncommon in North Carolina.  It would appear that the rarity of Lioplax in South Carolina may simply be a consequence of the species reaching the southern edge of its natural range.

> Ecology & Life History
The ecological literature contains few studies specifically addressing Lioplax. But judging from its biological similarity to Campeloma, one might infer that Lioplax has the ability to filter feed or suspension feed on fine organic particles. Unlike Campeloma, however, there is no evidence of parthenogenesis in Lioplax, as far as I am aware (Vail 1977). Vail (1978) reported a perennial, iteroparous life cycle for the population of Lioplax pilsbryi she studied in north Florida (Hi of Dillon 2000), animals requiring two years to mature.

> Essay
I published an essay reporting the rediscovery of Lioplax in South Carolina on 26Aug04. Photos of the habitat and the living animal are available from that page.

> Taxonomy & Systematics
Six nominal species of Lioplax are listed in Burch, but only L. subcarinata occurs in Atlantic drainages. The genus attracted considerable attention in the mid -20^th century, first from Clench (e.g. Clench & Turner 1955, Clench 1962) then from V. A. Vail, and has subsequently enjoyed a period of taxonomic stability. Vail (1977) has published a nice set of anatomical observations on Lioplax pilsbryi from north Florida.

>Maps of Lioplax distribution
Click the small map to enlarge it, or download the state-specific PDFs



North Carolina (PDF)

South Carolina (PDF)

>References
Dillon, R. T., Jr. (2000)  The Ecology of Freshwater Molluscs.  Cambridge University Press, United Kingdom.  509 pp.  Clench, W. (1962) New records of the genus Lioplax. Occas. Pprs. on Mollusks, Mus. Comp. Zool. Harvard, 2(27): 288. Clench, W. (1965) Supplement to the North American genus Lioplax. Occas. Pprs. on Mollusks, Mus. Comp. Zool. Harvard, 2(34): 426. Clench, W. & Turner, R. D. (1955) The North American genus Lioplax in the family Viviparidae. Occas. Pprs. on Mollusks, Mus. Comp. Zool. Harvard 2(19): 1 – 20.  Jokinen, E. (1992) The freshwater snails (Mollusca: Gastropoda) of New York State. New York State Museum Bulletin 482: 1-112. Vail, V.A. (1977) Comparative reproductive anatomy of 3 viviparid gastropods.  Malacologia 16: 519-520.  Vail, V.A. (1978)  Seasonal reproductive patterns in 3 viviparid gastropods.  Malacologia 17: 73-97. Vail, V.A. (1979)  A preliminary revision of Florida Lioplax (Gastropoda: Viviparidae) with a description of Lioplax talquinensis sp. nov. Malacol. Rev. 12: 87 – 88.