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Parastacoidea
The Parastacidae are the family of freshwater crayfish found in the Southern Hemisphere. The family is a classic Gondwana-distributed taxon, with extant members in South America, Madagascar, Australia, New Zealand, and New Guinea, and extinct taxa also in Antarctica. Distribution Three genera are found in Chile, ''Virilastacus'', ''Samastacus'' and '' Parastacus'', the last of which also occurs disjunctly in southern Brazil and Uruguay. There are no crayfish native to continental Africa, but seven species on Madagascar, all of the genus ''Astacoides''. Australasia is particularly rich in crayfish. The small genus '' Paranephrops'' is endemic to New Zealand. The genera '' Astacopsis'' is endemic to Tasmania, while a further two are found on either side of the Bass Strait – '' Geocharax'' and '' Engaeus''. The greatest diversity, however, is found on the Australian mainland. Three genera are endemic and have restricted distributions ('' Engaewa'', '' Gramastacus'' and '' Ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crayfish
Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mudbugs, baybugs or yabbies. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some species are found in brooks and streams, where fresh water is running, while others thrive in swamps, ditches, and paddy fields. Most crayfish cannot tolerate polluted water, although some species, such as '' Procambarus clarkii'', are hardier. Crayfish feed on animals and plants, either living or decomposing, and detritus. The term "crayfish" is applied to saltwater species in some countries. Terminology The name "crayfish" comes from the Old French word ' ( Modern French '). The word has been modified to "crayfish" by association with "fish" (folk etymology). The largely Amer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aenigmastacus
''Aenigmastacus crandalli'' is a species of fossil freshwater crayfish. It was found in early Eocene Okanagan Highlands lake deposits in British Columbia, and was described in 2011. It is the first member of the Gondwana-distributed family Parastacidae to be found in the Northern Hemisphere, and is the only species in the genus ''Aenigmastacus''. Twelve specimens are known, with a total body length of . On some specimens, details of the internal anatomy can be seen due to the exceptional preservation. Origin and description ''Aenigmastacus'' was discovered in the Tranquille Formations McAbee Fossil Beds of British Columbia, Canada,Feldmann ''et al.'' (2011), p. 320 at . The McAbee beds comprise a thickness of siliceous sediments within a sequence dominated by volcaniclastic rocks. They are formed from lake deposits, based on the presence of five families of freshwater fish and other terrestrial taxa, and the fossil-bearing sediments have been dated to the Ypresian (Lower Eoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engaewa
''Engaewa'' is a genus of burrowing crayfish belonging to the family Parastacidae. There are five recognised species, all endemic to the high-rainfall zone of south-west Western Australia, from Dunsborough to Albany. They are all small (up to 5 cm), and found only in freshwater swamps and seepages. Three of the five species are listed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and are listed on the IUCN Red List as "endangered" (EN) or "critically endangered" (CR), while the remaining two are listed as "Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. ...": References Parastacidae Endemic fauna of Southwest Australia Freshwater crustaceans of Australia Warren bioregion {{Crayfish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Swamp Crayfish
The eastern swamp crayfish (''Gramastacus lacus'') is a species of small freshwater crayfish from coastal New South Wales, Australia. It is distinguished from related species by large genital papilla on the males, large raised postorbital ridges, a laterally compressed carapace, and elongated chelae. Etymology The specific name is derived from Latin '' lacus'', referring to the coastal lakes that the species is found in. Before it was formally described it was known by the common name "lake yabby". Discovery Specimens of ''Gramastacus lacus'' were first discovered in the Ramsar wetlands of Myall Lakes National Park. More specimens were collected as part of the Australian Crayfish Project, starting in 2005. Description The species reaches a maximum weight of and a length of . The vast majority of specimens are smaller, with the average weight being around to . The rostum is long and narrow with a spine at the apex. The abdomen is smooth and unarmored, and thinly cover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma (million years ago). The Albian is preceded by the Aptian and followed by the Cenomanian. Stratigraphic definitions The Albian Stage was first proposed in 1842 by Alcide d'Orbigny. It was named after Alba, the Latin name for River Aube in France. A Global Boundary Stratotype Section and Point (GSSP), ratified by the IUGS in 2016, defines the base of the Albian as the first occurrence of the planktonic foraminiferan '' Microhedbergella renilaevis'' at the Col de Pré-Guittard section, Arnayon, Drôme, France. The top of the Albian Stage (the base of the Cenomanian Stage and Upper Cretaceous Series) is defined as the place where the foram species '' Rotalipora globotruncanoides'' first appears in the stratigraphic column. The Alb ... [...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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extant Taxon
Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, '' recent'') organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members still alive, as opposed to (all) being extinct. For example: * The moose (''Alces alces'') is an extant species, and the dodo (''Raphus cucullatus'') is an extinct species. * In the group of molluscs known as the cephalopods, there were approximately 600 extant species and 7,500 extinct species. A taxon can be classified as extinct if it is broadly agreed or certified that no members of the group are still alive. Conversely, an extinct taxon can be reclassified as extant if there are new discoveries of living species ("Lazarus species"), or if previously-known extant species are reclassified as members of the taxon. Most biologists, zoologists, and botanists are in practice neontologists, and the term neontologist is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virilastacus
''Virilastacus'' is a genus of freshwater burrowing crayfish species endemic to Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas .... It has four described species. The first species was described in 1914, but since 2005, three other species have been added to this genus. Species *''Virilastacus araucanius'' Faxon, 1914 *''Virilastacus jarai'' Erich H. Rudolph and Keith A. Crandall, 2012 *''Virilastacus retamali'' Erich H. Rudolph1 and Keith A. Crandall, 2007 *''Virilastacus rucapihuelensis'' Rudolph and Crandall, 2005http://oldredlist.iucnredlist.org/details/153746/0 IUCNRedlist.org/ References {{Taxonbar, from=Q18395466 Parastacidae Freshwater crustaceans of South America Edible crustaceans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa across the Mozambique Channel. At Madagascar is the world's second-largest island country, after Indonesia. The nation is home to around 30 million inhabitants and consists of the island of Madagascar (the fourth-largest island in the world), along with numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90% of its wildlife is endemic. Human settlement of Madagascar occurred during or before the mid first millennium AD by Austronesian peoples, presumably arriving on outrigger cano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
