Patera clarki nantahala
Encyclopedia
Patera clarki nantahala, common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

s the noonday globe, noonday snail or noonday helix, is a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 of the species Patera clarki
Patera clarki
Patera clarki, common name the Dwarf Proud Globe, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Polygyridae.- Subspecies :Subspecies within the species Patera clarki include:...

, a medium-sized, air-breathing land snail
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...

, a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 pulmonate gastropod mollusk in the family Polygyridae
Polygyridae
Polygyridae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea.The Polygyridae make up a significant proportion of the land snail fauna of eastern North America, and are also found in western North America, northern Central America, and...

.

The name "nantahala" is a Cherokee
Cherokee language
Cherokee is an Iroquoian language spoken by the Cherokee people which uses a unique syllabary writing system. It is the only Southern Iroquoian language that remains spoken. Cherokee is a polysynthetic language.-North American etymology:...

 word which means noon
Noon
Noon is usually defined as 12 o'clock in the daytime. The word noon is also used informally to mean midday regarding the location of the sun not the middle of a persons day. Although this is a time around the middle of the day when people in many countries take a lunch break...

day. This subspecies was given this name because the snail lives in a deep gorge where the sunshine does not reach the ground until the middle of the day.

Shell description

The shell
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 of the noonday globe snail is moderately sized (3/4 inch wide and 1/2 inch high) and globose in shape. The outer shell surface is shiny and reddish in color.

Shells of this subspecies often exhibit 5 and half whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

. The shell surface is sculptured with rather coarse lines. The area around the shell opening (aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

) is white, and a long curved "tooth" is located on the inside portion of the aperture.

The width of the shell is 18 mm. The height of the shell is 11 mm.

Distribution

Patera clarki nantahala is an endemic subspecies, part of the wildlife of North Carolina
Wildlife of North Carolina
This article seeks to serve as a field-guide, central repository, listing, and tour-guide for the flora and fauna of North Carolina and surrounding territories.-State ecology:...

.

Its distribution is restricted to part of the Nantahala Gorge, in the Appalachian Mountains
Appalachian Mountains
The Appalachian Mountains #Whether the stressed vowel is or ,#Whether the "ch" is pronounced as a fricative or an affricate , and#Whether the final vowel is the monophthong or the diphthong .), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians...

, in Swain County, North Carolina
Swain County, North Carolina
Swain County is a county located in the U.S. state of North Carolina. As of 2000, the population was 12,968. Its county seat is Bryson City.Swain County is home of the Nantahala River . The Nantahala is one of the most popular whitewater rafting rivers in the nation...

.

The noonday globe snail is known from a small area: approximately 2 miles of high cliff
Cliff
In geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually...

s within the Nantahala Gorge, on the east side of the gorge.

The noonday globe snail was probably never widely distributed. Its preferred habitat of steep wet slopes with calcareous rocks is rare in western North Carolina. However, the subspecies was probably more widely distributed within the gorge before the gorge itself was altered for a railroad and a highway
Highway
A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...

 U.S. Route 19
U.S. Route 19
U.S. Route 19 is a north–south U.S. Highway. Despite encroaching Interstate Highways, the route has remained a long-haul route, connecting the Gulf of Mexico with Lake Erie....

. Both of these projects altered the forest community
Community (ecology)
In ecology, a community is an assemblage of two or more populations of different species occupying the same geographical area. The term community has a variety of uses...

 along the river. The associated loss of the forest canopy
Canopy (forest)
In biology, the canopy is the aboveground portion of a plant community or crop, formed by plant crowns.For forests, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms .Sometimes the term canopy is used to refer to the extent...

 allowed more sunlight to penetrate the gorge, and dried out the lower slope. This habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

 alteration allowed such non-native plants as Kudzu
Kudzu
Kudzu is a plant in the genus Pueraria in the pea family Fabaceae, subfamily Faboideae. It is a climbing, coiling, and trailing vine native to southern Japan and southeast China. Its name comes from the Japanese name for the plant, . It is a weed that climbs over trees or shrubs and grows so...

 and Japanese honeysuckle
Japanese Honeysuckle
The Japanese Honeysuckle is a species of honeysuckle native to eastern Asia including China , Japan, and Korea. It is a twining vine able to climb up to high or more in trees, with opposite, simple oval leaves long and broad...

 to invade some roadside areas, and changed the area's natural plant and animal community.

In an attempt to secure the snail's continued existence, the United States Fish and Wildlife Service
United States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...

 added it as a threatened subspecies, to the Federal Endangered and Threatened Species List
United States Fish and Wildlife Service list of endangered species
This list contains only the bird and mammal species described as endangered by the United States Fish and Wildlife Service. It contains species not only in the U.S. and its territories, but also species only found abroad. It does not contain fish, amphibians, reptiles, plants, or invertebrates,...

 on July 3, 1978. It is a Federal offense punishable by as much as a $50,000 fine and one year in jail for taking a noonday snail.

Ecology

Because this snail is so rare and restricted in distribution, very little is known of its biology.

Habitat

This land snail is found in damp oak-hickory forest
Oak-hickory forest
The oak-hickory forest is a general type of North American forest ecosystem with a range extending from southern New England and New York, west to Iowa, and south to Northern Georgia. Smaller, isolated Oak-Hickory communities can also be found as far west as North Dakota, south to Florida and...

.

The cliffs in the Nantahala Gorge region are very wet, intersected by many small streams and waterfalls. The forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

 is mature, with many large trees and a diverse plant community. The forest floor has a thick, rich humus layer, and the area has many exposed 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....

 rocks. Calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...

, which is generally scarce in other cliffs in the area, is vital to most snails, because it is a major component of their shells. The rich, moist calcareous soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

s, and the mature forest community are likely to account for the unusually wide variety of snails which inhabit the area; Patera clarki nantahala being found in association
Association (ecology)
An association is the "ultimate classification level" of ecological systems. Local conditions permit several understory species to coexist with the same overstory dominants, and associations refer to the many co-occurring species rather than just the few dominant ones.Associations have:#A...

 with 29 other snail species.

This subspecies appears to be most active during wet weather, when it is frequently found out on the surface of vegetation, rather than under the leaf litter on the forest floor.

Feeding habits

The feeding habits of Patera clarki
Patera clarki
Patera clarki, common name the Dwarf Proud Globe, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Polygyridae.- Subspecies :Subspecies within the species Patera clarki include:...

are unknown, but other related species in the genus Patera feed on fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...

, in particular the subsurface, hair-like structures called (mycelia).

Interspecific relationships

Snails are usually exploited as a food source by other animals. A common carnivorous land snail, Haplotrema concavum
Haplotrema concavum
Haplotrema concavum, gray-footed lancetooth, is a species of predatory air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Haplotrematidae.- Feeding habits :...

, was observed eating a noonday globe snail, and gnawed shells of the other subspecies of this snail, Patera clarki
Patera clarki
Patera clarki, common name the Dwarf Proud Globe, is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Polygyridae.- Subspecies :Subspecies within the species Patera clarki include:...

 clarki
, have been found in the dens of small rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

s.

Further reading

  • Author unknown, March 13 1996. (DRAFT) SNAIL, NOONDAY. available at http://fwie.fw.vt.edu/WWW/esis/lists/e354003.htm
  • U.S. Fish and Wildlife Service. 1984. Recovery Plan for the Noonday Snail. U.S. Fish and Wildlife Service. Atlanta, GA. 30 pp.
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