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Athearnia
''Athearnia'' is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Pleuroceridae. Species Species within the genus ''Athearnia'' include: * ''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 ...'' * '' Athearnia crassa'', the boulder snail References * Zipcode zoo info at Pleuroceridae {{Pleuroceridae-stub pt:Athearnia anthonyi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
Athearnia Crassa
''Athearnia crassa'', the boulder snail, was a species of freshwater snail in the family Pleuroceridae. It was native to the United States, where it was known from Alabama, Georgia, Tennessee, and Virginia. It is now extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and .... References Molluscs of the United States Pleuroceridae Extinct gastropods Gastropods described in 1841 Taxa named by Samuel Stehman Haldeman Taxonomy articles created by Polbot {{Pleuroceridae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boulder Snail
''Athearnia crassa'', the boulder snail, was a species of freshwater snail in the family Pleuroceridae. It was native to the United States, where it was known from Alabama, Georgia, Tennessee, and Virginia. It is now extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and .... References Molluscs of the United States Pleuroceridae Extinct gastropods Gastropods described in 1841 Taxa named by Samuel Stehman Haldeman Taxonomy articles created by Polbot {{Pleuroceridae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...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] |
Gill
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. Branchia (pl. branchiae) is the zoologists' name for gills (from Ancient Greek ). With the exception of some aquatic insects, the filaments and lamellae (folds) contain blood or coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body. Carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including mollusks, crustaceans, insects, fish, and amphibians. Semiterrestrial marine animals such as crabs and mudskippers have gill cham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
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 re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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