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Euastacus
''Euastacus'' is a genus of fresh water, freshwater crayfish known as "spiny crayfish". They are found in the south-east of the Australian mainland, along with another genus of crayfish, ''Cherax''. Both genera are members of the family Parastacidae, a family of freshwater crayfish restricted to the Southern Hemisphere. ''Euastacus'' crayfish are distinguished from the smooth-shelled ''Cherax'' species by the short robust spikes on their claws and carapace, and frequently, their larger size. Many ''Euastacus'' species grow to a relatively large size, with the Murray crayfish, Murray River crayfish (''Euastacus armatus'') being the second largest freshwater crayfish species in the world. (The largest freshwater crayfish in the world is the Tasmanian giant freshwater crayfish (''Astacopsis gouldi''), found on the Australian island of Tasmania, and the genus ''Astacopsis'' is now known to be a very closely related sister genus to ''Euastacus''.) The genera ''Cherax'' and ''Euastac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euastacus Australasiensis
''Euastacus'' is a genus of freshwater crayfish known as "spiny crayfish". They are found in the south-east of the Australian mainland, along with another genus of crayfish, ''Cherax''. Both genera are members of the family Parastacidae, a family of freshwater crayfish restricted to the Southern Hemisphere. ''Euastacus'' crayfish are distinguished from the smooth-shelled ''Cherax'' species by the short robust spikes on their claws and carapace, and frequently, their larger size. Many ''Euastacus'' species grow to a relatively large size, with the Murray River crayfish (''Euastacus armatus'') being the second largest freshwater crayfish species in the world. (The largest freshwater crayfish in the world is the Tasmanian giant freshwater crayfish (''Astacopsis gouldi''), found on the Australian island of Tasmania, and the genus ''Astacopsis'' is now known to be a very closely related sister genus to ''Euastacus''.) The genera ''Cherax'' and ''Euastacus'' continue a trend prese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euastacus Armatus
The Murray crayfish, ''Euastacus armatus'', is a species of freshwater crayfish endemic to Australia that belongs to the family Parastacidae. The Murray crayfish has the largest geographic range of any of the ''Euastacus'' crayfish in Australia, being found in the Murray and Murrumbidgee Rivers as well as many of their tributaries. Murray crayfish are also known as "Murray River crayfish", "Murray crays", "freshwater crays", "spiny freshwater crays", "spinies" and in the Wagga Wagga region of southern New South Wales they are simply known as "lobsters". Today adults commonly grow to in length. In the past however they have been reliably recorded at significantly larger lengths and up to in weight; the Murray crayfish is considered the second largest freshwater crayfish species in the world after the Tasmanian giant freshwater crayfish. Murray crayfish have large white claws and a dark olive/grey/black carapace, all of which are covered in short robust spikes. In small individ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellen Clark
Ellen Clark (1915–1988) was an Australian carcinologist and naturalist, whose work focused on crustaceans and ants Clark studied, named, described and published many of the Australian freshwater crayfish species. By 1939, she was reported to have identified more than half the known species of Australian crayfish. She conducted research about blood groups in crustaceans and made a significant contribution to the study of crayfish genera. She was the first woman to publish in the ''Memoirs of the National Museum of Victoria''. Ellen Clark's crayfish, ''Euastacus clarkae'', was named after Clark in recognition of her pioneering parastacid studies. Clark's work has had a lasting legacy and is still being debated in scientific papers. References Australian scientists 1915 births 1988 deaths Women naturalists 20th-century Australian women {{Australia-scientist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crayfish
Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. 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" ( French language">Modern French '). The word has been modified to "crayfish" by association with "fish" ( American variant "crawfish" is similarly derived. Some kinds of crayfish are known lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parastacidae
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. Classification and phylogeny Parastacidae belongs to the superfamily Parastacoidea, the monotypic taxon which contains all crayfish in the Southern Hemisphere. Parastacoidea is the sister taxon to Astacoidea, which contains all crayfish of the Northern Hemisphere. Crayfish and lobsters together comprise the infraorder Astacidea, as shown in the simplified cladogram below: 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. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherax
''Cherax'', commonly known as yabby/yabbies in Australia, is the most widespread genus of fully aquatic crayfish in the Southern Hemisphere. Various species of cherax may be found in both still and flowing bodies of freshwater across most of Australia and New Guinea. Together with '' Euastacus'', it is also the largest crayfish genus in the Southern Hemisphere. Habitat Members of the cherax genus can be found in lakes, rivers, and streams across most of Australia and New Guinea. The most common and widely distributed species in Australia is the common yabby (''C. destructor''). It is generally found in lowland rivers and streams, lakes, swamps, and impoundments at low to medium altitude, largely within the Murray–Darling Basin. Common yabbies are found in many ephemeral waterways, and can survive dry conditions for long periods of time (at least several years) by aestivating (lying dormant) in burrows sunk deep into muddy creek and swamp beds. In New Guinea, ''Cherax'' cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered Species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, invasive species, and climate change. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration. Human activity is a significant cause in causing some species to become endangered. Conservation status The conservation status of a species indicates the likelihood that it will become extinct. Multiple factors are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological species. A series of Regional Red Lists, which assess the risk of extinction to species within a political management unit, are also produced by countries and organizations. The goals of the Red List are to provide scientifically based information on the status of species and subspecies at a global level, to draw attention to the magnitude and importance of threatened biodiversity, to influence national and international policy and decision-making, and to provide information to guide actions to conserve biological diversity. Major species assessors include BirdLife International, the Institute of Zoology (the research division of the Zoological Society of London), the World Conservation Monitoring Centre, and many Specialist Groups w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critically Endangered
An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of the 157,190 species currently on the IUCN Red List, 9,760 of those are listed as critically endangered, with 1,302 being possibly extinct and 67 possibly extinct in the wild. The IUCN Red List provides the public with information regarding the conservation status of animal, fungi, and plant species. It divides various species into seven different categories of conservation that are based on habitat range, population size, habitat, threats, etc. Each category represents a different level of global extinction risk. Species that are considered to be critically endangered are placed within the "Threatened" category. As the IUCN Red List does not consider a species extinct until extensive targeted surveys have been conducted, species that a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
