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Stichocotylida
''Stichocotyle'' is a monospecific genus of trematodes, in the monospecific family Stichocotylidae, which is itself in the monotypic order Stichocotylida. It comprises the single species ''Stichocotyle nephropis'', which is an internal parasite of elasmobranch fishes. It was originally described from the Norway lobster, ''Nephrops norvegicus'', by J. T. Cunningham in 1884. This flatworm is distinguished by a single ventral row of well separated suckers. ''Stichocotyle'' has not been seen since 1986, and it is possible that it is extinct. Like many parasites, it relied on multiple hosts, and its disappearance is hypothesized to be associated with declines in some of these hosts. The thornback ray ''Raja clavata'' and the barndoor skate ''Dipturus laevis'' were hosts for the adult form, and have declined because they are killed as bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Thomas Cunningham
Joseph Thomas Cunningham (1859–1935) was a British Marine biology, marine biologist and Zoology, zoologist known for his experiments on flatfish and his writings on Lamarckism, neo-Lamarckism. Career Cunningham worked at the Barts and The London School of Medicine and Dentistry, London Hospital Medical College. He completed his science scholarship at Balliol College, Oxford. Cunningham was a neo-Lamarckian. In his book ''Hormones and Heredity'' (1921) he proposed that the mechanism for the inheritance of acquired characteristics were hormones. He termed this "chemical Lamarckism". According to science historian Peter J. Bowler the idea held by Cunningham that hormones transferred from one generation to the next independent of the germ plasm was seen at the time by neo-Lamarckians as a plausible hypothesis, however "its advocates were unable to get beyond the stage of providing indirect evidence for the effect they postulated." Experiments In a series of experiments (in 1891, 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematode
Trematoda is a Class (biology), class of flatworms known as trematodes, and commonly as flukes. They are obligate parasite, obligate Endoparasites, internal parasites with a complex biological life cycle, life cycle requiring at least two Host (biology), hosts. The intermediate host, in which asexual reproduction occurs, is a Mollusca, mollusk, usually a snail. The definitive host, where the flukes Sexual reproduction, sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five vertebrate classes: mammals, birds, amphibians, reptiles, and fish. Etymology Trematodes are commonly referred to as flukes. This term can be traced back to the Old English name for flounder, and refers to the flattened, rhomboidal shape of the organisms. The etymology of trematode stems from the Ancient Greek, Greek word ''trēmatṓdēs'', which means "pierced with holes", and refers to the worm's sucker (zoology), sucker, which pierces a hole in the host while the worm is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitism
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) 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 characterised parasites' way of feeding 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: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasmobranchii
Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including modern sharks ( division Selachii), and batomorphs (division Batomorphi, including rays, skates, and sawfish). Members of this subclass are characterised by having five to seven pairs of gill slits opening individually to the exterior, rigid dorsal fins and small placoid scales on the skin. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The details of this jaw anatomy vary between species, and help distinguish the different elasmobranch clades. The pelvic fins in males are modified to create claspers for the transfer of sperm. There is no swim bladder; instead, these fish maintain buoyancy with large livers rich in oil. The definition of the clade is unclear with respect to fossil chondrichthyans. Some authors consider it as equivalent to Neoselachii (the crown group clade including modern sharks, rays, and all o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nephrops Norvegicus
''Nephrops norvegicus'', known variously as the Norway lobster, Dublin Bay prawn, ' (compare langostino) or ''scampi'', is a slim, coral-colored lobster that grows up to long, and is "the most important commercial crustacean in Europe". It is now the only extant species in the genus '' Nephrops'', after several other species were moved to the closely related genus ''Metanephrops''. It lives in the north-eastern Atlantic Ocean, and parts of the Mediterranean Sea, but is absent from the Baltic Sea and Black Sea. Adults emerge from their burrows at night to feed on worms and fish. Description ''Nephrops norvegicus'' has the typical body shape of a lobster, albeit narrower than the larger-bodied genus ''Homarus''. It is pale orange in colour, and grows to a typical length of , or exceptionally long, including the tail and claws. A carapace covers the animal's cephalothorax, while the abdomen is long and segmented, ending in a broad tail fan. The first three pairs of legs bear cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Invertebrate Pathology
The ''Journal of Invertebrate Pathology'' is a peer-reviewed scientific journal publishing research on the induction and pathogenesis of diseases of invertebrates, owned by Academic Press (part of Elsevier). The journal publishes the results of physiological, morphological, genetic, immunological, and ecological studies as related to the etiologic agents of diseases of invertebrates, including the suppression of diseases in beneficial species, and the use of diseases in controlling undesirable species. It was founded by American microbiologist Edward Arthur Steinhaus in 1959 as the ''Journal of Insect Pathology'', renamed in 1965, and in 1968 adopted as the official journal of the Society for Invertebrate Pathology shortly after it was also founded by Steinhaus. See also * Arbovirus Arbovirus is an informal name for any virus that is Transmission (medicine), transmitted by arthropod Vector (epidemiology), vectors. The term ''arbovirus'' is a portmanteau word (''ar''thropo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thornback Ray
The thornback ray (''Raja clavata''), or thornback skate, is a species of ray (fish), ray fish in the family Rajidae. Distribution The Thornback ray is found in the Atlantic coastal waters of Europe and western Africa. It is also present from South Africa to the southwestern Indian Ocean and in the Mediterranean and Black Seas. It is native possibly as far south as Namibia and South Africa. Its natural habitats are open large seas and shallow seas. It is sometimes seen trapped in large estuary, estuarine pools at low tide. The thornback ray is probably one of the most common ray (fish), rays encountered by divers. Habitat The thornback ray is usually found on sedimentary seabeds such as mud, sand or gravel at depths between 10–60m. Juvenile fish feed on small crustaceans, particularly amphipods and bottom-living shrimps; adults feed on crabs, shrimps and small fish. Description Like all rays, the thornback ray has a flattened body with broad, wing-like pectoral fins. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species ( freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as rough fish (mainly US) or coarse fish (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 1990 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasites Of Crustaceans
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) 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 characterised parasites' way of feeding 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 endoparas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematode Genera
Trematoda is a Class (biology), class of flatworms known as trematodes, and commonly as flukes. They are obligate parasite, obligate Endoparasites, internal parasites with a complex biological life cycle, life cycle requiring at least two Host (biology), hosts. The intermediate host, in which asexual reproduction occurs, is a Mollusca, mollusk, usually a snail. The definitive host, where the flukes Sexual reproduction, sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five vertebrate classes: mammals, birds, amphibians, reptiles, and fish. Etymology Trematodes are commonly referred to as flukes. This term can be traced back to the Old English name for flounder, and refers to the flattened, rhomboidal shape of the organisms. The etymology of trematode stems from the Ancient Greek, Greek word ''trēmatṓdēs'', which means "pierced with holes", and refers to the worm's sucker (zoology), sucker, which pierces a hole in the host while the worm is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Platyhelminthes Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
