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Seisonidea
Seisonidae is a family of rotifers, found on the gills of ''Nebalia'', a marine crustacean. Peculiar among rotifers, males and females are both present and equal in size. Males and females are similar with paired gonads. It is considered to have diverged from the other rotifers early on, and in one treatment is placed in a separate class Seisonoidea. They have a large and elongate body with reduced corona. Their muscular system is similar to that of other rotifers: they have longitudinal muscles as well as open annular muscles. Species Two genera with total three species belong to Seisonidae: * ''Paraseison'' Plate, 1887 ** ''Paraseison annulatus'' (Claus, 1876) — ectoparasite of ''Nebalia'' * ''Seison'' Grube, 1861 ** ''Seison nebaliae'' Grube, 1861 – commensal of ''Nebalia'' ** ''Seison africanus ''Seison'' is a genus of rotifers belonging to the family Seisonidae. Species: *'' Seison africanus'' *''Seison nebaliae ''Seison'' is a genus of rotifers belonging ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotifer
The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John Harris in 1696, and other forms were described by Antonie van Leeuwenhoek in 1703. Most rotifers are around long (although their size can range from to over ), and are common in freshwater environments throughout the world with a few saltwater species. Some rotifers are free swimming and truly planktonic, others move by inchworming along a substrate, and some are sessile, living inside tubes or gelatinous holdfasts that are attached to a substrate. About 25 species are colonial (e.g., '' Sinantherina semibullata''), either sessile or planktonic. Rotifers are an important part of the freshwater zooplankton, being a major foodsource and with many species also contributing to the decomposition of soil organic matter. Most species of the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraseison
''Paraseison'' is a monotypic genus of rotifers The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ... belonging to the family Seisonidae. The only species is ''Paraseison annulatus''. The species is found in Europe and Northern America. References Pararotatoria Rotifer genera Monotypic animal genera {{rotifer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seison
''Seison'' is a genus of rotifers The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ... belonging to the family Seisonidae. Species: *'' Seison africanus'' *'' Seison nebaliae'' References {{Taxonbar, from=Q1042298 Rotifer genera Pararotatoria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nebalia
''Nebalia'' is a large genus of small crustaceans containing more than half of the species in the order Leptostraca, and was first described by William Elford Leach in 1814. The genus contains over thirty species: *'' Nebalia abyssicola'' Ledoyer, 1997 *'' Nebalia antarctica'' Dahl, 1990 *'' Nebalia biarticulata'' Ledoyer, 1997 *''Nebalia bipes'' (Fabricius, 1780) *'' Nebalia borealis'' Dahl, 1985 *'' Nebalia brucei'' Olesen, 1999 *'' Nebalia cannoni'' Dahl, 1990 *'' Nebalia capensis'' Barnard, 1914 *''Nebalia clausi'' Dahl, 1985 *'' Nebalia dahli'' Kazmi & Tirmizi, 1989 *'' Nebalia daytoni'' Vetter, 1996 *'' Nebalia falklandensis'' Dahl, 1990 *''Nebalia geoffroyi'' Milne-Edwards, 1928 *''Nebalia gerkenae'' Haney & Martin, 2000 *'' Nebalia herbstii'' Leach, 1814 *''Nebalia hessleri'' Martin, Vetter & Cash-Clark, 1996 *''Nebalia ilheoensis'' Kensley, 1976 *''Nebalia kensleyi'' Haney & Martin, 2005 *''Nebalia kocatasi'' Moreira, Kocak & Katagan, 2007 *''Nebalia lagartensis'' Escoba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals have a type of gonad called an ovotestis. Evolution It is hard to find a common origin for gonads, but gonads most likely evolved independently several times. Regulation The gonads are controlled by luteinizing hormone and follicle-stimulating hormone, produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone produced in the hypothalamus. Development Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of genital ridges, which are only l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (biology)
In biological classification, class ( la, classis) is a taxonomic rank, as well as a taxonomic unit, a taxon, in that rank. It is a group of related taxonomic orders. Other well-known ranks in descending order of size are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order. History The class as a distinct rank of biological classification having its own distinctive name (and not just called a ''top-level genus'' ''(genus summum)'') was first introduced by the French botanist Joseph Pitton de Tournefort in his classification of plants that appeared in his ''Eléments de botanique'', 1694. Insofar as a general definition of a class is available, it has historically been conceived as embracing taxa that combine a distinct ''grade'' of organization—i.e. a 'level of complexity', measured in terms of how differentiated their organ systems are into distinct regions or sub-organs—with a distinct ''type'' of construction, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraseison Annulatus
''Paraseison'' is a monotypic genus of rotifers The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ... belonging to the family Seisonidae. The only species is ''Paraseison annulatus''. The species is found in Europe and Northern America. References Pararotatoria Rotifer genera Monotypic animal genera {{rotifer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectoparasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes. There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), trophicallytransmitted parasitism (by being eaten), vector-transmitted parasitism, parasitoidism, and micropredation. One major axis of classification concerns invasiveness: an endoparasite lives inside the host's body; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seison Nebaliae
''Seison'' is a genus of rotifers The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ... belonging to the family Seisonidae. Species: *'' Seison africanus'' *'' Seison nebaliae'' References {{Taxonbar, from=Q1042298 Rotifer genera Pararotatoria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commensalism
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit from each other; amensalism, where one is harmed while the other is unaffected; parasitism, where one is harmed and the other benefits, and parasitoidism, which is similar to parasitism but the parasitoid has a free-living state and instead of just harming its host, it eventually ends up killing it. The commensal (the species that benefits from the association) may obtain nutrients, shelter, support, or locomotion from the host species, which is substantially unaffected. The commensal relation is often between a larger host and a smaller commensal; the host organism is unmodified, whereas the commensal species may show great structural adaptation consistent with its habits, as in the remoras that ride attached to sharks and other fishes. Remo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
