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Chain Catshark
The chain catshark or chain dogfish (''Scyliorhinus retifer'') is a small, reticulated catshark that is biofluorescent. The species is common in the Northwest Atlantic, Gulf of Mexico and Caribbean. It is harmless and rarely encountered by humans. It has very similar reproductive traits to the small-spotted catshark (''S. canicula''). Distribution The chain catshark is found in the Northwest Atlantic, Gulf of Mexico and Caribbean, ranging from George's Bank in Massachusetts, to Nicaragua and Barbados. In the Mid-Atlantic Bight, the chain catshark is found along the outer continental shelf and upper slope. The shark occupies depths of ; in the northern part of its range it is mainly found between and in the southern areas generally deeper than . Due to the shark's depth distribution, it has been suggested that the shark does not perform large-scale migrations. Temperature is thought to limit the shark's distribution in northern areas, particularly during the winter. Although ban ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Garman
Samuel Walton Garman (June 5, 1843 – September 30, 1927), or "Garmann" as he sometimes styled himself, was a naturalist/zoologist from Pennsylvania. He became noted as an ichthyologist and herpetologist. Biography Garman was born in Indiana County, Pennsylvania, on 5 June 1843. In 1868 he joined an expedition to the American West with John Wesley Powell. He graduated from the Illinois State Normal University in 1870, and for the following year was principal of the Mississippi State Normal School. In 1871, he became professor of natural sciences in Ferry Hall Seminary, Lake Forest, Illinois, and a year later became a special pupil of Louis Agassiz. He was a friend and regular correspondent of the naturalist Edward Drinker Cope, and in 1872 accompanied him on a fossil hunting trip to Wyoming. In 1870 he became assistant director of herpetology and ichthyology at Harvard's Museum of Comparative Zoology. His work was mostly in the classification of fish, especially sharks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nidamental Gland
Nidamental glands are internal organs found in some elasmobranchs and certain molluscs, including cephalopods (specifically Decapodiformes and nautiluses) and gastropods.Young, R.E., M. Vecchione & K.M. Mangold (1999)Cephalopoda Glossary Tree of Life Web Project. In cephalopods, nidamental glands are large, paired glandular structures found in the mantle cavity. Accessory nidamental glands may also be present. Nidamental glands are composed of lamellae Lamella (plural lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * ... and are involved in the secretion of egg cases or the gelatinous substance comprising egg masses. They are also found in phoronids. Culinary uses Nidamental glands of cuttlefish are eaten as food in various parts of the world, included either in dishes in which the whole animal is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kynurenine Pathway
400px, The kynurenine pathway The kynurenine pathway is a metabolic pathway leading to the production of nicotinamide adenine dinucleotide (NAD+). Metabolites involved in the kynurenine pathway include tryptophan, kynurenine, kynurenic acid, xanthurenic acid, quinolinic acid, and 3-hydroxykynurenine. The kynurenine pathway is responsible for total catabolization of tryptophan about 95%. Disruption in the pathway is associated with certain genetic and psychiatric disorders. Kynurenine pathway dysfunction Disorders affecting the kynurenine pathway may be primary (of genetic origin) or secondary (due to inflammatory conditions). Peripheral inflammation can lead to a build up of kynurenine in the brain, and this is associated with major depressive disorder, bipolar disorder, and schizophrenia. Dysfunction of the pathway not only cause increasing metabolites such as quinolinic acid or kynurenic acid but also affects serotonin and melatonin synthesis. Kynurenine clearance in exerc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kynurenine
-Kynurenine is a metabolite of the amino acid -tryptophan used in the production of niacin. Kynurenine is synthesized by the enzyme tryptophan dioxygenase, which is made primarily but not exclusively in the liver, and indoleamine 2,3-dioxygenase, which is made in many tissues in response to immune activation. Kynurenine and its further breakdown products carry out diverse biological functions, including dilating blood vessels during inflammation and regulating the immune response. Some cancers increase kynurenine production, which increases tumor growth. Evidence suggests that increased kynurenine production may precipitate depressive symptoms associated with interferon treatment for hepatitis C. Cognitive deficits in schizophrenia are associated with imbalances in the enzymes that break down kynurenine. Blood levels of kynurenine are reduced in people with bipolar disorder. Kynurenine production is increased in Alzheimer's disease and cardiovascular disease where its metabolit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swell Shark
The swell shark (''Cephaloscyllium ventriosum'') is a catshark in the family Scyliorhinidae. It is found in the tropical and subtropical eastern Pacific Ocean from between central California to southern Mexico, with an additional population off the coast of Chile. As a defense, the swell shark is able to expand to approximately double its regular size by swallowing water. Taxonomy When discovered in 1880, the swell shark was first described as ''Scyllium ventriosum'', but was later changed to ''Cephaloscyllium ventriosum''. The genus name comes from the Greek word ''kephale'', which means "head", and ''skylla'', which means a certain kind of shark. The species name comes from the Latin word ''ventrĭōsus'', which means "large-bellied". The species name refers to its ability to enlarge itself by taking in water. Distribution and habitat The swell shark is found in the eastern Pacific Ocean, from the central California coast to southern Mexico. There is an additional population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasmobranch
Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of gill clefts 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. It has been used by different authors as equivalent to Neoselachii (the clade including modern sharks and rays and their last common ancestor) or for al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yolk Sac
The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is far more widely used. In humans, the yolk sac is important in early embryonic blood supply, and much of it is incorporated into the primordial gut during the fourth week of embryonic development. In humans The yolk sac is the first element seen within the gestational sac during pregnancy, usually at 3 days gestation. The yolk sac is situated on the front (ventral) part of the embryo; it is lined by extra-embryonic endoderm, outside of which is a layer of extra-embryonic mesenchyme, derived from the epiblast. Blood is conveyed to the wall of the yolk sac by the primitive aorta and after circulating through a wide-meshed capillary plexus, is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the vitell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gill Filaments
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. Branchia (pl. branchiae) is the zoologists' name for gills (from Ancient Greek ). With the exception of some aquatic insects, the filaments and lamellae (folds) contain blood or coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body. Carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including mollusks, crustaceans, insects, fish, and amphibians. Semiterrestrial marine animals such as crabs and mudskippers have gill ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gill Arches
Branchial arches, or gill arches, are a series of bony "loops" present in fish, which support the gills. As gills are the primitive condition of vertebrates, all vertebrate embryos develop pharyngeal arches, though the eventual fate of these arches varies between taxa. In jawed fish, the first arch develops into the jaws, the second into the hyomandibular complex, with the posterior arches supporting gills. In amphibians and reptiles, many elements are lost including the gill arches, resulting in only the oral jaws and a hyoid apparatus remaining. In mammals and birds, the hyoid is still more simplified. All basal vertebrates breathe with gills. The gills are carried right behind the head, bordering the posterior margins of a series of openings from the esophagus to the exterior. Each gill is supported by a cartilaginous or bony gill arch. Bony fish have four pairs of arches, cartilaginous fish have five to seven pairs, and primitive jawless fish have seven. The vertebrate a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blastodisc
The blastodisc, also called the germinal disc, is the embryo-forming part on the yolk of the egg of an animal that undergoes discoidal meroblastic cleavage. Discoidal cleavage occurs in those animals with a large proportion of yolk in their eggs, and include insects, fish, reptiles and birds. The blastodisc is a small disc of cytoplasm that sits on top of the yolk. In birds it is a small, circular, white spot (approximately 1.5-3 mm across) on the surface of the yellow yolk of an egg, at the animal pole In developmental biology, an embryo is divided into two hemispheres: the animal pole and the vegetal pole within a blastula. The animal pole consists of small cells that divide rapidly, in contrast with the vegetal pole below it. In some cases, the .... References Early Development in Fish [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scyliorhinus Retifer Eggs
''Scyliorhinus'' is a genus of catsharks in the family Scyliorhinidae. This genus is known in the fossil records from the Cretaceous period, late Albian age to the Pliocene epoch.Carrier, J. C.; Musick, J. A. & Heithaus, M. R. (2004)''Biology of Sharks and Their Relatives'' Species There are currently 16 recognized species in this genus: * ''Scyliorhinus boa'' Goode & T. H. Bean, 1896 (boa catshark) * ''Scyliorhinus cabofriensis'' K. D. A. Soares, U. L. Gomes & M. R. de Carvalho, 2016Soares, K.D.A., Gomes, U.L. & De Carvalho, M.R. (2016): Taxonomic review of catsharks of the ''Scyliorhinus haeckelii'' group, with the description of a new species (Chondrichthyes: Carcharhiniformes: Scyliorhinidae). ''Zootaxa, 4066 (5): 501-534.'' * ''Scyliorhinus canicula'' (Linnaeus, 1758) (small-spotted catshark) * ''Scyliorhinus capensis'' ( J. P. Müller & Henle, 1838) (yellowspotted catshark) * ''Scyliorhinus cervigoni'' Maurin & M. Bonnet, 1970 (West African catshark) * ''Scyliorhinus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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