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''Leptoxis ampla'', common name the round rocksnail, is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Pleuroceridae. This species is endemic to the United States, specifically the state of Alabama. The snail has been listed as threatened on the United States Fish and Wildlife Service list of endangered species since 28 October 1998.〔Fish and Wildlife Service. (28 October 1998). ("Endangered and Threatened Wildlife and Plants; Endangered Status for Three Aquatic Snails, and Threatened Status for Three Aquatic Snails in the Mobile River Basin of Alabama" ). ''Federal Register'' 63(208), Rules and Regulations, Accessed 26 January 2009.〕 ''Leptoxis ampla'' is a vulnerable species according to the IUCN Red list.〔 == Description == The round rocksnail is a pleurocerid snail and its shell grows to about 20 mm (0.8 in) in length. The shell is subglobose, with an ovately rounded aperture. The body whorl is shouldered at the suture, and may be ornamented with folds or plicae. Color may be yellow, dark brown, or olive green, usually with four entire or broken bands.〔Goodrich C. (1922). "The Anculosae of the Alabama River Drainage". ''Miscellaneous Publications'', Museum of Zoology, University of Michigan (7): 1-57.〕〔 Lydeard et al. (1997) found slight differences in DNA sequencing between the painted rocksnail and the round rocksnail, and considered them to be sister species. Following analysis by allozyme electrophoresis on these same species, Dillon〔Dillon, in litt., 1997〕 speculated that the two species represented isolated populations belonging to a single species. The two species are geographically separated, with the painted rocksnail inhabiting Coosa River tributaries, and the round rocksnail inhabiting the Cahaba River drainage. Both species are currently recognized by the malacological community.〔〔Burch J. B. (1989). "North American freshwater snails". ''Malacological Publications'', Hamburg, Michigan. 365 pp.〕〔Turgeon D. D., Quinn J. F. Jr., Bogan A. E., Coan E. V., Hochberg F. G., Lyons W. G., Mikkelsen P. M., Neves R. J., Roper C. F. E., Rosenberg G., Roth B., Scheltema A., Thompson F. G., Vecchione M. & Williams J. D. (1998). "Common and scientific names of aquatic invertebrates from the United States and Canada: mollusks". Am. Fish. Soc. Special Publication 26: 36.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Leptoxis ampla」の詳細全文を読む スポンサード リンク
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