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Valvata Virens
''Valvata virens'' is a species of freshwater snail in the family Valvatidae. It is known by the common name emerald valvata.NatureServe. 2014''Valvata virens''.NatureServe Explorer. Version 7.1. Accessed September 3, 2014. This species is endemic to California in the United States. Reports from adjacent states are invalid. Of the two valid occurrences reported in California, at least one is extirpated and the other is in an unknown location. NatureServe has listed the species with the conservation status The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ... "possibly extinct". References Valvatidae Endemic fauna of California Taxa named by George Washington Tryon Taxonomy articles created by Polbot {{Valvatidae-stub ... [...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] |
Freshwater Snail
Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs to major rivers. The great majority of freshwater gastropods have a shell, with very few exceptions. Some groups of snails that live in freshwater respire using gills, whereas other groups need to reach the surface to breathe air. In addition, some are amphibious and have both gills and a lung (e.g. ''Ampullariidae''). Most feed on algae, but many are detritivores and some are filter feeders. According to a 2008 review of the taxonomy, there are about 4,000 species of freshwater gastropods (3,795–3,972). At least 33–38 independent lineages of gastropods have successfully colonized freshwater environments. It is not possible to quantify the exact number of these lineages yet, because they have yet to be clarified within the Cerit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of California
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NatureServe Conservation Status
The NatureServe conservation status system, maintained and presented by NatureServe in cooperation with the Natural Heritage Network, was developed in the United States in the 1980s by The Nature Conservancy (TNC) as a means for ranking or categorizing the relative imperilment of species of plants, animals, or other organisms, as well as natural ecological communities, on the global, national or subnational levels. These designations are also referred to as NatureServe ranks, NatureServe statuses, or Natural Heritage ranks. While the Nature Conservancy is no longer substantially involved in the maintenance of these ranks, the name TNC ranks is still sometimes encountered for them. NatureServe ranks indicate the imperilment of species or ecological communities as natural occurrences, ignoring individuals or populations in captivity or cultivation, and also ignoring non-native occurrences established through human intervention beyond the species' natural range, as for example w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NatureServe
NatureServe, Inc. is a non-profit organization based in Arlington County, Virginia, US, that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and the public. NatureServe reports being "headquartered in Arlington, Virginia, with regional offices in four U.S. locations and in Canada." In calendar year 2011 they reported having 86 employees, 6 volunteers, and 15 independent officers. History The Nature Conservancy reports that in 2000 it spun off its 85-center Natural Heritage Network "into a new independent organization, the Association for Biodiversity Information (later renamed NatureServe)." NatureServe reports that it was established in 1994 as the Association for Biodiversity Information. In 2001 the IRS approved a name change to NatureServe that was requested in 1999, while maintaining the organization's 501(c)(3) tax-exempt status granted in July 1995. NatureServe's website declares that it i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Extinction
Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a change in the ecology of an area. In recent times, local extinction has sometimes been followed by a replacement of the species taken from other locations; wolf reintroduction is an example of this. The term "local extinction" is highly vernacular. The more proper biological term is ''extirpation''. Discussion Glaciation can lead to local extinction. This was the case during the Pleistocene glaciation event in North America. During this period, most of the native North American species of earthworm were killed in places covered by glaciation. This left them open for colonization by European earthworms brought over in soil from Europe. Species naturally become extirpated from islands over time. The number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territories of the United States by population, most populous U.S. state and the List of U.S. states and territories by area, 3rd largest by area. It is also the most populated Administrative division, subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous Statistical area (United States), urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento, California, Sacramento is the state's capital, while Los Angeles is the List of largest California cities by population, most populous city in the state and the List of United States cities by population, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Washington Tryon
George Washington Tryon Jr. (20 May 1838 – 5 February 1888) was an American malacologist who worked at the Academy of Natural Sciences in Philadelphia. Biography George Washington Tryon was the son of Edward K. Tryon and Adeline Savidt. In 1853 he attended the Friends Central School in Philadelphia. In 1859, Tryon became a member of the Academy of Natural Sciences of Philadelphia. He was largely responsible for the construction of new buildings for the Academy, especially, in 1866, a section for malacology. In 1869 he became the conservator in this malacological section. In 1865, together with a group of American malacologists, he founded (and financed) the American Journal of Conchology. This ended in 1872. In 1879 he started the ''Manual of Conchology; structural and systematic; with illustrations of the species'', volume 1, series 1. When he died, nine volumes of the first series had been published. From 1887 until 1888, his assistant was Henry Augustus Pilsbry. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valvata
''Valvata'' is a genus of very small freshwater snails with an operculum, aquatic gastropod mollusks in the family Valvatidae, the valve snails.Bouchet, P.; Rosenberg, G. (2014). Valvata O. F. Müller, 1774. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153994 on 2014-11-15 Synonyms * ''Cincinna'' Hübner, 1810 · accepted, alternate representation (''Cincinna'' is treated as subgenus of ''Valvata'') * ''Cincinna (Atropidina)'' Lindholm, 1906 (subgenus-genus combination invalid; ''Atropidina'' is considered a junior synonym of ''Tropidina'' or ''Cincinna'' (depending on source); to avoid problems we refer to ''Valvata'' only) * ''Cincinna (Cincinna)'' Hübner, 1810 (''Cincinna'' is treated as subgenus of ''Valvata'') * ''Gyrorbis'' Fitzinger, 1833 (junior synonym (?)) * ''Planorbis (Gyrorbis)'' Fitzinger, 1833 (junior synonym (?)) * ''Valvata (Atropidina)'' Lindholm, 1906 (type species of ''Atropidina'' (Valvata pulc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valvatidae
''Valvatidae'', the valve snails, is a taxonomic family of very small freshwater snails with an operculum, aquatic gastropod mollusks. Taxonomy The family Valvatidae has no subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). Genera The type genus of this family is ''Valvata'' O.F. Müller, 1774. Genera in the family Valvatidae include: * '' Andrussovia'' Brusina, 1903 * ''Borysthenia'' Lindholm, 1933 * '' Costovalvata'' Polinski, 1932 * '' Liratina'' Lindholm, 1906 * '' Megalovalvata'' Lindholm, 1906 * '' Valvata'' Müller, 1774 ** '' Cincinna'' Hübner, 1810 - It is recognized either as genus Anistratenko O., Degtyarenko E., Anistratenko V. (2010). "Сравнительная морфология раковины и радулы брюхоногих моллюсков семейства Valvatidae из Северного Причерноморья. hell and radula comparative morphology of the Gastropod Molluscs family Valvatidae from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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