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Athearnia Anthonyi
''Athearnia anthonyi'' is a rare species of freshwater snail in the family Pleuroceridae. Its common name is Anthony's riversnail. It is native to three rivers in the Tennessee River system in the United States: the main branch and the Sequatchie River The Sequatchie River is a waterway that drains the Sequatchie Valley, a large valley in the Cumberland Plateau in Tennessee. It empties into the Tennessee River downstream from Chattanooga near the Tennessee-Alabama state line. Hydrography The ... and Limestone Creek.USFWS''Athearnia anthonyi'' Five-year Review.March 2011. References Pleuroceridae Gastropods described in 1854 ESA endangered species {{Pleuroceridae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non- salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive. Fresh wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snail
A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastropoda that have a coiled shell that is large enough for the animal to retract completely into. When the word "snail" is used in this most general sense, it includes not just land snails but also numerous species of sea snails and freshwater snails. Gastropods that naturally lack a shell, or have only an internal shell, are mostly called '' slugs'', and land snails that have only a very small shell (that they cannot retract into) are often called ''semi-slugs''. Snails have considerable human relevance, including as food items, as pests, and as vectors of disease, and their shells are used as decorative objects and are incorporated into jewelry. The snail has also had some cultural significance, tending to be associated with lethargy. The sn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleuroceridae
Pleuroceridae, common name pleurocerids, is a family of small to medium-sized freshwater snails, aquatic gilled gastropod mollusks in the superfamily Cerithioidea.These snails have an operculum and typically a robust high-spired shell. Reproduction is iteroparous, and juvenile snails emerge from eggs laid on a firm surface by a gonochoristic female. There is no veliger stage. Distribution As currently defined, this family is confined entirely to eastern North American fresh waters. Similar snails formerly classified with Pleuroceridae, but now assigned to other families are widespread in temperate and tropical parts of Southern and Eastern Asia, and Africa. Most require unpolluted rivers and streams, but a few are adapted to living in lakes or reservoirs. Taxonomy 2005 taxonomy The following two subfamilies have been recognized in the taxonomy of Bouchet & Rocroi (2005): * Pleurocerinae P. Fischer, 1885 - synonyms: Ceriphasiinae Gill, 1863; Strepomatidae Haldeman, 1864 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennessee River
The Tennessee River is the largest tributary of the Ohio River. It is approximately long and is located in the southeastern United States in the Tennessee Valley. The river was once popularly known as the Cherokee River, among other names, as the Cherokee people had their homelands along its banks, especially in what are now East Tennessee and northern Alabama. Additionally, its tributary, the Little Tennessee River, flows into it from Western North Carolina and northeastern Georgia, where the river also was bordered by numerous Cherokee towns. Its current name is derived from the Cherokee town, ''Tanasi'', which was located on the Tennessee side of the Appalachian Mountains. Course The Tennessee River is formed at the confluence of the Holston and French Broad rivers in present-day Knoxville, Tennessee. From Knoxville, it flows southwest through East Tennessee into Chattanooga before crossing into Alabama. It travels through the Huntsville and Decatur area before rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequatchie River
The Sequatchie River is a waterway that drains the Sequatchie Valley, a large valley in the Cumberland Plateau in Tennessee. It empties into the Tennessee River downstream from Chattanooga near the Tennessee-Alabama state line. Hydrography The Sequatchie River originates from several springs at or neaDevilstep Hollow Cave including the spring, Head of the Sequatchie. Dye traces establish the origin of their water as originating from Grassy Cove, the pastoral limestone sinkhole located to the north-east. The Sequatchie River follows the general trend of the Sequatchie Valley, flowing south-west for . The stream crosses into Bledsoe County near the head of the Sequatchie Valley. The Sequatchie Valley is traversed throughout much its length by U.S. Route 127. The first sizeable town on the Sequatchie is Pikeville, the county seat of Bledsoe. State Route 30, which descends Walden's Ridge into the Valley and then climbs the escarpment back onto the plateau, crosses here. Cros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropods Described In 1854
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, and reproduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
