Anguispira picta, common names painted snake-coiled forest snail and painted tigersnail, is a rare species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Discidae, the disc snails. It is a limestone specialist, and is limited to outcrops with suitable mineralogy.[3][4]
| Painted snake-coiled forest snail | |
|---|---|
| |
| A live individual in situ | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Order: | Stylommatophora |
| Family: | Discidae |
| Genus: | Anguispira |
| Species: | A. picta
|
| Binomial name | |
| Anguispira picta (G. H. Clapp, 1920)
| |
A. picta was first discovered in 1906. It was once treated as a subspecies of the more common Anguispira cumberlandiana, but it is now regarded as a unique species. This species is native to the Cumberland Plateau in Tennessee, and is currently only found in Franklin County. It may possibly also occur just over the border in Alabama, although populations have not yet been located.[5] The U.S. Fish and Wildlife Service has federally listed the species as threatened.
Appearance
editA picta possesses a depressed dome-shaped shell with 6 whorls and a nearly smooth white carina. The base of the shell is pale, usually cream in color, and defined by brown or chestnut blotches that radiate outwards along the whorls.[3] Adults typically range from 17-21 mm in width and 9-10 mm in height.[6] The shell of A. picta is notably less compressed and striated than other limestone specialists such as Anguispira cumberlandiana and Anguispira alabama.
Ecology
editA picta was long thought to be endemic to one cove on the edge of the Cumberland Plateau, near the town of Sherwood, Tennessee along the Crow Creek drainage.[6] The cove is heavily forested (hardwood dominant) and studded with large limestone outcrops.[4] The snail still occurs at this cove and is abundant there. Recent surveys demonstrate that its distribution extends a few miles past the cove. Until recently, its entire distribution was located on privately owned land. In 2018, a land grant to the Sherwood Forest, part of South Cumberland State Park, included one-third of the snail's known range, and is now a protected area.[7][8]
Like some other members of the Anguispira genus, A. picta is a limestone specialist. Snails have rarely been observed on any other habitat besides limestone, and when they were, outcrops were always in the immediate area. The presence of Monteagle limestone, a type of limestone found only in the Cumberland Plateau region, may be a potential prerequisite for A. picta habitation.[4] Since Monteagle limestone is not the dominant geologic formation in the surrounding area, A. picta may be prevented from expanding its range.[4]
Threats
editThreats to the species include residential development, which can alter the habitat indirectly by adding polluted surface runoff into waterways. There is active limestone quarrying in the area, which can destroy habitat and cause habitat fragmentation. Logging also removes forest cover; the snail can apparently tolerate some degree of deforestation, but the long-term impacts on its survival are not yet known.[8]
References
edit- ^ Roth, B. (1996). "Anguispira picta". IUCN Red List of Threatened Species. 1996: e.T1299A3404225. doi:10.2305/IUCN.UK.1996.RLTS.T1299A3404225.en. Retrieved 20 October 2023.
- ^ NatureServe (6 October 2023). "Anguispira picta". NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer. Arlington, Virginia: NatureServe. Retrieved 20 October 2023.
- ^ a b USFWS. Painted snake coiled forest snail 5-year Review. (2016)
- ^ a b c d Withers, D.I. 2003. Distributional surveys for the painted snake coiled forest snail (Anguispira picta). Final Report. Unpublished report to the U.S. Fish and Wildlife Service, Tennessee Division of Natural Heritage, Revenue Grant #1448-40181-02-G-051. 20 pp.
- ^ Anguispira picta. The Nature Conservancy.
- ^ a b USFWS. Painted snake coiled forest snail Recovery Plan. (October 1982).
- ^ "Sherwood Forest addition wins Governor's 2017 Environmental Stewardship Award". Friends of South Cumberland State Park.
- ^ a b USFWS. Painted snake coiled forest snail Five-year Review. (January 2008).
External links
edit- Roth, B. (1996). "Anguispira picta". IUCN Red List of Threatened Species. 1996: e.T1299A3404225. doi:10.2305/IUCN.UK.1996.RLTS.T1299A3404225.en. Retrieved 15 November 2021.