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The Chittenango ovate amber snail, scientific name ''Novisuccinea chittenangoensis'', is a species of small air-breathing land snail in the family Succineidae, the amber snails. This species was discovered in 1905, and was reported three years later as a subspecies of the oval ambersnail, ''Succinea ovalis''. Several taxonomic reviews took place in the subsequent decades until the end of the 1980s, when the Chittenango ovate amber snail was finally judged to be a distinct species ''Novisuccinea chittenangoensis'', based on chemical and morphological data. The Chittenango ovate amber snail is endemic to the Chittenango area of Madison County, New York, United States. There is only one population of this species at Chittenango Falls State Park in central New York, even though it was believed to have a broader range previously; based on fossil records, some authors argue that the distribution of this species may have been much wider in the past. In opposition to this, other authors argue that it is impossible to identify this species based on fossil records, because they only allow for examination of shell features. Shell features of species in this particular family of snails are usually not very distinctive. ''Novisuccinea chittenangoensis'' has a small (an average of 20.9 mm in length in adult individuals), delicate, ovate shell of 3¼ whorls, with deep sutures. The shell is almost translucent, and varies in color from a chalky pale yellow to white, with a glossy surface. Several internal organs of the animal can be distinguished through the shell's outer surface. The visible soft parts of the animal are of a pale subtranslucent yellow color, with different markings during distinct stages of development. Studies on the ecology of the Chittenango ovate amber snail are fairly recent. It is an herbivorous species which lives in the fresh spray zone of the Chittenango Falls, in partially sunlit areas with lush herbaceous growth. Several parameters appear to be influential in its habitat selection, namely humidity, substrate, temperature, vegetation, and water quality. ''Novisuccinea chittenangoensis'' is a hermaphroditic species, and its mating season is from May through July. It lays egg clusters, each one containing an average of 8 to 14 eggs, at the base of plants, under matted vegetation, or in loose, wet soil. Maturity is reached in five to eight months, and its life span is roughly 2.5 years. Some of its predators include insects, amphibians, mammals, birds, and occasionally other snails. Since the time of its discovery in 1905, there have been many attempts to estimate the population size of this species. Results varied greatly, but the more recent ones suggest a very reduced number of individuals. This coupled with a very restricted distribution have led to the listing of ''Novisuccinea chittenangoensis'' as an endangered or threatened species. Humans frequently invade its habitat, though such disturbances have been greatly reduced by preventive measures. Recent efforts in conservation include perpetuating the extant population at a baseline size as well as maintaining captive populations. == Taxonomy == The snail was first discovered at Chittenango Falls in August 1905 by a field party from the Academy of Natural Sciences of Philadelphia. In 1908, Henry Augustus Pilsbry reported the discovery, describing the snail as a subspecies of the widely distributed ''Succinea ovalis''. Because of this, the Chittenango ovate amber snail is referred to in many publications as ''Succinea ovalis chittenangoensis''.〔〔Solem A. (1976). "Status of ''Succinea ovalis chittenangoensis'' Pilsbry, 1908". ''The Nautilus'' 90(3): (107 )-114.〕〔 Pilsbry placed ''Succinea ovalis'' in the subgenus ''Novisuccinea'' in 1948.〔Pilsbry H. A. (1948). ''Land mollusca of North America (north of Mexico). Vol. 2., Part 2.'' The Academy of Natural Sciences of Philadelphia. Monograph 3. 2(2): 771-790; 801-808.〕 Alan Solem (1976)〔 considered this snail to be merely a form of ''Succinea ovalis'', citing similarities in genitalia and radula, and attributing shell differences to, possibly, a marked genetic mutation. Grimm (1981) considered it to be a distinct species due to external morphological differences (color and shell shape).〔Grimm F. W. (1981). "A review of the Chittenango ovate amber snail, ''Succinea chittenangoensis'', Pilsbry, 1908 - a Pleistocene relict now greatly restricted in distribution". Contract report to the New York State Department of Environmental Conservation Endangered Species Unit. 30 pp.〕 By 1981, ''Succinea ovalis'' could not be found at the Falls; however, during sampling for Hoagland’s electrophoretic analyses, ''Succinea ovalis'' was found at two locations within approximately 16 kilometers of Chittenango Falls. Individuals assigned to ''Novisuccinea chittenangoensis'' appeared to be divided into two color morphs, a "gray morph" that was relatively common and widespread at the Falls, and a "red morph" that was restricted to the ledges at the base of the Falls. A preliminary analysis by Hoagland (1984)〔Hoagland K. E. (1984). "The succineid snail fauna of Chittenango Falls, New York: Taxonomic Status and Population Genetics". Final contract report to New York State Dept. of Environmental Conservation under Federal Aid to Endangered Species Project E-1-7. 36 pp.〕 stated unequivocally that the red and the gray morphs were two distinct species, possibly in separate genera. Solem examined specimens of the gray morph and assigned it to ''Succinea putris'', an introduced snail possibly from Europe which appears to crowd out all other species.〔〔〔Solem A. (8 May 1985). Field Museum of Natural History, Chicago. Personal communication. In: U.S. Fish and Wildlife Service. (2006).〕 Hoagland and Davis (1987) subsequently completed a thorough analysis, based on electrophoresis, shell morphology, and internal anatomy, of the succineids at Chittenango Falls. They divided ''Succinea'' into two genera, keeping the Old World ''Succinea'' in the genus and elevating the New World ''Succinea'', of the Section ''Novisuccinea'' including ''ovalis'' and ''chittenangoensis'', to the genus level.〔〔Hoagland K. E. & Davis G. M. (1987). "The succineid snail fauna of Chittenango Falls, New York: taxonomic status with comparisons to other relevant taxa". ''Proceedings of the Academy of Natural Sciences of Philadelphia'' 139: (465 )-526.〕 They also determined that the Old World ''Succinea putris'' is probably a species complex and that the gray morph, although closely related to ''Succinea putris'' sensu lato, is a distinct species, which they designated ''Succinea'' sp. B. Based on these factors, the species designation ''Novisuccinea chittenangoensis'' is considered valid. Both species have been observed with red and gray morphs, bringing into question whether the earlier separation truly represented taxonomic distinctiveness. Currently, ''Novisuccinea chittenangoensis'', ''Succinea'' sp. B, and 3–4 ''Oxyloma'' spp.〔 are considered to be the only succineid species present at Chittenango Falls.〔 In 2003, the U.S. Geological Survey (T. King, unpublished data) amplified and sequenced the cytochrome oxidase I region of mitochondrial DNA and the ITS-1 region of nuclear DNA in ''Novisuccinea chittenangoensis'' and ''Succinea'' sp. B. The results (sequence divergence of 10–15 percent) suggest large differences between the two species. No hybridization was observed.〔 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「Chittenango ovate amber snail」の詳細全文を読む スポンサード リンク
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