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Astropecten Latespinosus
''Astropecten latespinosus'' is a species of starfish in the family Astropectinidae. It is one of the commonest starfish in the seas around Japan. The name in Japanese is hira momiji, "hira" meaning ''flattened'' and "momiji" meaning ''maple leaves tinged with bright red'', a name given to certain starfish which resemble maple leaves in form. Description ''Astropecten latespinosus'' is a five-armed starfish with a brownish flattened body and a fringe of pale-coloured spines round the margins of the short, tapered arms. Biology Unlike many members of this genus, the larva of ''Astropecten latespinosus'' is not a brachiolaria larva but is barrel-shaped and undergoes metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ... at a very early stage of development. References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Meissner
George Meissner (19 November 1829 – 30 March 1905) was a German anatomist and physiologist born in Hanover. He studied medicine at the University of Göttingen, where he worked closely with Rudolf Wagner (1806–1864). In 1851 he accompanied Wagner and Theodor Billroth (1829–1894) on an expedition to Trieste, where he performed scientific studies of torpedo fish. In 1852 he earned his doctorate at Göttingen, and was later a university professor at Basel (from 1855), Freiburg (from 1857) and Göttingen (1860–1901). His name is associated with Meissner's corpuscles, which are mechanoreceptors that are responsible for sensitivity to light touch. They were first described in 1852, with Meissner and Wagner each feeling that he alone should be given priority as to discovery of the corpuscles. A controversy took place between the two men, causing a strained relationship that lasted for several years. His name is also associated with Meissner's plexus, being described as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starfish
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at below the surface. Starfish are marine invertebrates. They typically have a central disc and usually five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astropectinidae
The Astropectinidae are a family of sea stars in the order Paxillosida. Usually, these starfish live on the seabed and immerse themselves in soft sediment such as sand and mud. They are not to be confused with species in the genus '' Archaster'', which share similar shape and life habits, but belong to the family Archasteridae (order Valvatida). Genera There are 27 genera in the family: * '' Astromesites'' Fisher, 1913 * ''Astropecten'' Gray, 1840 * '' Astropectinides'' Verrill, 1914 * '' Bathybiaster'' Danielssen & Koren, 1883 * '' Blakiaster'' Perrier, 1881 * '' Bollonaster'' McKnight, 1977 * '' Bunodaster'' Verrill, 1909 * '' Craspidaster'' Sladen, 1889 * '' Ctenophoraster'' Fisher, 1906 * '' Ctenopleura'' Fisher, 1913 * '' Dipsacaster'' Alcock, 1893 * '' Dytaster'' Sladen, 1889 * '' Koremaster'' Fisher, 1913 * '' Leptychaster'' E.A. Smith, 1876 * '' Lonchotaster'' Sladen, 1889 * '' Macroptychaster'' H.E.S. Clark, 1963 * '' Mimastrella'' Fisher, 1916 * '' Patagiaster'' Fisher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maple
''Acer'' () is a genus of trees and shrubs commonly known as maples. The genus is placed in the family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated since http://www.mobot.org/MOBOT/research/APweb/. There are approximately 132 species, most of which are native to Asia, with a number also appearing in Europe, northern Africa, and North America. Only one species, ''Acer laurinum'', extends to the Southern Hemisphere.Gibbs, D. & Chen, Y. (2009The Red List of Maples Botanic Gardens Conservation International (BGCI) The type species of the genus is the sycamore maple, '' Acer pseudoplatanus'', the most common maple species in Europe.van Gelderen, C. J. & van Gelderen, D. M. (1999). ''Maples for Gardens: A Color Encyclopedia'' Maples usually have easily recognizable palmate leaves ('' Acer negundo'' is an exception) and distinctive winged fruits. The closest relatives of the maples are the horse c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachiolaria
A brachiolaria is the second stage of larval development in many starfishes. It follows the bipinnaria. Brachiolaria have bilateral symmetry, unlike the adult starfish, which have a pentaradial symmetry. Starfish of the order Paxillosida (''Astropecten'' and '' Asterina'') have no brachiolaria stage, with the bipinnaria developing directly into an adult. The brachiolaria develops from the bipinnaria larva when the latter grows three short arms at the underside of its anterior end. These arms each bear sticky cells at the tip, and they surround an adhesive sucker. The larva soon sinks to the bottom, attaching itself to the substrate, firstly with the tips of the arms, and then with the sucker. Once attached, it begins to metamorphose into the adult form. The adult starfish develops only from the hind-part of the larva, away from the sucker. It is from this part that the arms of the adult grow, with the larval arms eventually degenerating and disappearing. The digestive system of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transformation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
