Painted snake-coiled forest snail
Encyclopedia
Anguispira picta is a rare species of snail
known by the common names painted snake-coiled forest snail and painted tigersnail. It is a member of family Discidae
, the disc snails. It is native to Tennessee
in the United States, where it is known only from Franklin County
. It may possibly occur just over the border in Alabama
. It is a federally listed threatened species of the United States.
This snail was first discovered in 1906. It was once treated as a subspecies of the more common Anguispira cumberlandiana
. It is now a species in its own right. The snail is about 2 centimeters wide and 1 high. Its shape is a depressed dome. The shell has six whorls which are whitish with brownish blotches. The juvenile has a translucent and brightly colored shell.
This snail was long thought to be endemic to one cove
on the edge of the Cumberland Plateau
, near the town of Sherwood, Tennessee. The cove is heavily forested and studded with limestone
outcrops, and it has a creek running through. The snail still occurs at this cove and it is abundant there. Recent surveys demonstrate that its distribution extends a few miles past the cove. Its entire distribution is located on privately owned land.
Threats to the species include residential development, which can alter the habitat indirectly, such as by adding polluted surface runoff
to the 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 an amount of deforestation
, but the long-term effects are not yet known.
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
known by the common names painted snake-coiled forest snail and painted tigersnail. It is a member of family Discidae
Discidae
Discidae is a taxonomic family of small air-breathing land snails, terrestrial gastropod mollusks in the superfamily Punctoidea.-Genera:The family Discidae has no subfamilies...
, the disc snails. It is native to Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
in the United States, where it is known only from Franklin County
Franklin County, Tennessee
Franklin County is a county located in the U.S. state of Tennessee. As of 2010, the population was 41,052. Its county seat is Winchester.Franklin County is part of the Tullahoma, Tennessee, Micropolitan Statistical Area.-History:...
. It may possibly occur just over the border in Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
. It is a federally listed threatened species of the United States.
This snail was first discovered in 1906. It was once treated as a subspecies of the more common Anguispira cumberlandiana
Anguispira cumberlandiana
The Cumberland Tigersnail or the Cumberland Disc, scientific name Anguispira cumberlandiana, is a species of small, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Discidae....
. It is now a species in its own right. The snail is about 2 centimeters wide and 1 high. Its shape is a depressed dome. The shell has six whorls which are whitish with brownish blotches. The juvenile has a translucent and brightly colored shell.
This snail was long thought to be endemic to one cove
Cove
A cove is a small type of bay or coastal inlet. They usually have narrow, restricted entrances, are often circular or oval, and are often inside a larger bay. Small, narrow, sheltered bays, inlets, creeks, or recesses in a coast are often considered coves...
on the edge of the Cumberland Plateau
Cumberland Plateau
The Cumberland Plateau is the southern part of the Appalachian Plateau. It includes much of eastern Kentucky and western West Virginia, part of Tennessee, and a small portion of northern Alabama and northwest Georgia . The terms "Allegheny Plateau" and the "Cumberland Plateau" both refer to the...
, near the town of Sherwood, Tennessee. The cove is heavily forested and studded with limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
outcrops, and it has a creek running through. The snail still occurs at this cove and it is abundant there. Recent surveys demonstrate that its distribution extends a few miles past the cove. Its entire distribution is located on privately owned land.
Threats to the species include residential development, which can alter the habitat indirectly, such as by adding polluted surface runoff
Surface runoff
Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
to the waterways. There is active limestone quarrying in the area, which can destroy habitat and cause habitat fragmentation
Habitat fragmentation
Habitat fragmentation as the name implies, describes the emergence of discontinuities in an organism's preferred environment , causing population fragmentation...
. Logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
also removes forest cover; the snail can apparently tolerate an amount of deforestation
Deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
, but the long-term effects are not yet known.
External links
- Roth, B. (1996). Anguispira picta. 2011 IUCN Red List of Threatened Species. Downloaded on 4 October 2011.