|
The Kanab ambersnail, scientific name ''Oxyloma haydeni kanabense'' or ''Oxyloma kanabense'', is a critically endangered subspecies or species of small, air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Succineidae, the amber snails. The common name of the amber snails is based on the shell, which is translucent and when empty usually resembles amber in color.〔 This species is endemic to the United States, specifically the state of Arizona and Utah, where it was first collected in the early 20th century. It has been listed as endangered on the United States Fish and Wildlife Service list of endangered species since 8 August 1991. This snail lives in wetlands, springs, and seeps, and only two of its natural habitats are known to exist: Three Lakes, a meadow near Kanab, Utah, and ''Vasey's Paradise'', a spring along the Colorado River within Grand Canyon National Park.〔 In its natural habitat it is rather polyphagous, feeding mainly on bacteria, plants and fungi, and reproduces during the summer. Now considered a Critically Endangered species on the IUCN Red List of Threatened Species〔 due to a series of factors (including anthropic influence〔), the Kanab ambersnail has been reintroduced to three springs above the historic high water level along the Colorado River. ==Taxonomy== Specimens of the Kanab ambersnail were first collected in 1909 by James Ferriss from: "The Greens", above Kanab, Utah on Kanab Wash, on a wet ledge among moss and ''Cypripediums''. These specimens were originally thought to belong to the species ''Succinea hawkinsi''.〔〔 Pilsbry (1948)〔 transferred these specimens to the genus ''Oxyloma'' and erected the subspecies ''kanabensis'' in the species ''haydeni'' for them. Arthur Clarke (1991) notes that Pilsbry’s decision to accord the Kanab ambersnail subspecific status was preliminary, and that, as Pilsbry himself noted, ''“its taxonomic status should be reevaluated.”'' Clarke (1991)〔Clarke, A.H. 1991. ''Status survey of selected land and freshwater gastropods in Utah''. Unpublished report prepared for the U.S. Fish and Wildlife Service, Denver, Colorado. 70 pp + cxii.〕 and Shei K. Wu (Colorado Museum of Natural History, Boulder, Colorado, pers. comm. 1992, 1995)〔 suggest that the Kanab ambersnail may deserve full species status. Earle Spamer (Academy of Natural Sciences of Philadelphia, Philadelphia, Pennsylvania, pers. comm. 1994)〔 stated that although current published mollusk checklists (Turgeon et al. 1988 and Groombridge 1993) treat the Kanab ambersnail at species level rather that as a subspecies, nonetheless, until the criteria are derived (and published) by which the taxon can be known to be a separate species, it should continue to be called by its original name, the one published by Pilsbry (1948): ''Oxyloma haydeni'' spp. ''kanabensis''.〔 Despite this, NatureServe does list this taxon as a species.〔(''Oxyloma kanabense''. NatureServe, accessed 19 August 2009. )〕 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「Kanab ambersnail」の詳細全文を読む スポンサード リンク
|