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Ethusa Mascarone
''Ethusa mascarone'' is a species of crabs in the family Ethusidae. Description The cephalothorax of ''Ethusa mascarone'' is almost rectangular, it can reach a length of and a width of . The body color is gray-brown, with brown lines on the carapace and transverse striae on the abdomen. Chelipeds and legs are lighter and white speckled. The front pairs of legs are long, but the hind legs are shorter and are used to carry on the back a variety of objects and organisms, especially valves of bivalves, by which these crabs camouflage and protect themselves. It has been described as a decorator crab despite not belonging to the superfamily Majoidea The Majoidea are a Superfamily (taxonomy), superfamily of crabs which includes the various spider crabs. Taxonomy In "''A classification of living and fossil genera of decapod crustaceans''" De Grave and colleagues divided Majoidea into six fa .... They mainly feed on small organisms and decaying flesh of dead animals. Distribution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Wilhelm Herbst
Johann Friedrich Wilhelm Herbst (1 November 1743 – 5 November 1807) was a German naturalist and entomologist from Petershagen, Minden-Ravensberg. He served as a chaplain in the Prussian army. His marriage in Berlin, 1770, with Euphrosyne Luise Sophie (1742–1805), daughter of the Prussian ''Hofrat'' Libert Waldschmidt seems to have been childless. He was the joint editor, with , of ''Naturgeschichte der in- und ausländischen Insekten'' (1785–1806, 10 volumes), which was one of the first attempts at a complete survey of the order [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period. Description Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a pair of chelae (claws). Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span up to . Several other groups of crustaceans with similar appearances – such as king crabs and porcelain crabs – are not true crabs, but have evolved features similar to true crabs through a process known as carcinisation. Environment Crabs are found in all of the world's oceans, as well as in fresh w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethusidae
Ethusidae is one of two extant families of crabs in the superfamily Dorippoidea. It contains four genera. Members of this family are found in marine environments at depths from 16m to 4,192m. Genera *'' Ethusa'' Roux, 1830 *'' Ethusina'' Smith, 1884 *'' Parethusa'' Chen, 1997 *'' Serpenthusa'' Naruse, Castro & Ng, 2009 References *Ng, Guinot & Davie (2008). ''Systema Brachyurorum: Part I. An annotated checklist of extant brachyuran crabs of the world.'' Raffles Bulletin of Zoology Supplement, n. 17 . Crabs Decapod families {{crab-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decorator Crab
Decorator crabs are crabs of several different species, belonging to the superfamily Majoidea (not all of which are decorators), that use materials from their environment to hide from, or ward off, predators. They decorate themselves by sticking mostly sedentary animals and plants to their bodies as camouflage, or if the attached organisms are noxious, to ward off predators through aposematism. History In 1889, William Bateson observed in detail the way that decorator crabs fix materials on their backs. He noted that "the whole proceeding is most human and purposeful", and that if a '' Stenorhynchus'' crab is cleaned, it will "''immediately'' begin to clothe itself again with the same care and precision as before". In his ''The Colours of Animals'' (1890), Edward Bagnall Poulton classified protective animal coloration into types such as warning colours and protective mimicry. He included self decoration under the heading "Adventitious Protection", quoting Bateson's account of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Majoidea
The Majoidea are a Superfamily (taxonomy), superfamily of crabs which includes the various spider crabs. Taxonomy In "''A classification of living and fossil genera of decapod crustaceans''" De Grave and colleagues divided Majoidea into six families: * Family Epialtidae ** Subfamily Epialtinae ** Subfamily Pisinae ** Subfamily Pliosomatinae ** Subfamily Tychiinae * Family Hymenosomatidae * Family Inachidae * Family Inachoididae * Family Majidae ** Subfamily Eurynolambrinae ** Subfamily Majinae ** Subfamily Micromaiinae ** Subfamily Mithracinae ** Subfamily Planoterginae * Family Oregoniidae The classification has since been revised, with subfamilies Epialtinae and Mithracinae being elevated to families and Hymenosomatidae being moved to its own superfamily. The family composition according to the World Register of Marine Species is as follows: * family Epialtidae MacLeay, 1838 * family Inachidae MacLeay, 1838 * family Inachoididae Dana, 1851 * family Macrocheiridae Dana, 1851 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxia (environmental)
Hypoxia refers to low oxygen conditions. Normally, 20.9% of the gas in the atmosphere is oxygen. The partial pressure of oxygen in the atmosphere is 20.9% of the total barometric pressure. In water, oxygen levels are much lower, approximately 7 ppm or 0.0007% in good quality water, and fluctuate locally depending on the presence of photosynthetic organisms and relative distance to the surface (if there is more oxygen in the air, it will diffuse across the partial pressure gradient). Atmospheric hypoxia Atmospheric hypoxia occurs naturally at high altitudes. Total atmospheric pressure decreases as altitude increases, causing a lower partial pressure of oxygen, which is defined as hypobaric hypoxia. Oxygen remains at 20.9% of the total gas mixture, differing from hypoxic hypoxia, where the percentage of oxygen in the air (or blood) is decreased. This is common in the sealed burrows of some subterranean animals, such as blesmols. Atmospheric hypoxia is also the basis of altitude tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crabs
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period. Description Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a pair of chelae (claws). Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span up to . Several other groups of crustaceans with similar appearances – such as king crabs and porcelain crabs – are not true crabs, but have evolved features similar to true crabs through a process known as carcinisation. Environment Crabs are found in all of the world's oceans, as well as in fresh w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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