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Scyliorhinoidei
Scyliorhinidae is a family of sharks, one of a few families whose members share the common name catsharks, belonging to the order Carcharhiniformes, the ground sharks. Although they are generally known as catsharks, some species can also be called dogfish due to previous naming. However, a dogfish may generally be distinguished from a catshark as catsharks lay eggs while dogfish have live young. Like most bottom feeders, catsharks feed on benthic invertebrates and smaller fish. They are not harmful to humans. The family is paraphyletic, containing several distinct lineages that do not form a monophyletic group. Genera Scyliorhinidae includes the following genera: * '' Cephaloscyllium'' T. N. Gill, 1862 * ''Poroderma'' A. Smith, 1838 * ''Scyliorhinus'' Blainville, 1816 Anatomy and appearance Scyliorhinidae catsharks may be distinguished by their elongated, cat-like eyes and two small dorsal fins set far back. Most species are fairly small, growing no longer than 80&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcharhiniformes
Carcharhiniformes ( from Classical Greek ' (karcharos) 'sharp/jagged' and ' (rhinos) 'nose', plus Latin ''forme'' 'shape'), commonly known as ground sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and requiem sharks. Members of this order are characterized by the presence of a nictitating membrane over the eye, two dorsal fins, an anal fin, and five gill slits. The families in the order Carcharhiniformes are expected to be revised; recent DNA studies show that some of the conventional groups are not monophyletic. The oldest members of the order appeared during the Middle-Late Jurassic, which have teeth and body forms that are morphologically similar to living catsharks. Carchariniformes first underwent major diversification during the Late Cretaceous, initially as mostly small-sized forms, before radiating into medium and large body sizes during the Cenozoic. Families Eschmeyer's Catalog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitesaddled Catshark
The whitesaddled catshark (''Scyliorhinus hesperius'') is a species of catshark, and part of the family Scyliorhinidae. It is found on the upper continental slope of the western central Atlantic Ocean, off the coasts of Honduras, Panama and Colombia, between latitudes 22° N and 9° N, at depths between . It can grow to a length of . The reproduction of this catshark is oviparous but otherwise, little is known about its biology. Description The whitesaddled catshark is a moderately small, slender catshark that reaches a maximum length of . The front of the first dorsal fin is located above and just behind the base of the pelvic fin and the front of the second dorsal fin is located above the hind third of the base of the anal fin. The first dorsal fin is considerably larger than the second and the distance between the two is about the same as the length of the anal fin. The skin is fairly smooth and there are small, flat denticles. There are seven or eight dark saddles on the ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scyliorhinus
''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) * ''Scyliorhin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scyliorhinidae
Scyliorhinidae is a Family (biology), family of sharks, one of a few families whose members share the common name catsharks, belonging to the Order (biology), order Carcharhiniformes, the ground sharks. Although they are generally known as catsharks, some species can also be called dogfish due to previous naming. However, a dogfish may generally be distinguished from a catshark as catsharks lay eggs while dogfish have live young. Like most bottom feeders, catsharks feed on benthic invertebrates and smaller fish. They are not harmful to humans. The family is paraphyletic, containing several distinct lineages that do not form a monophyletic group. Genera Scyliorhinidae includes the following genera: * ''Cephaloscyllium'' Theodore Gill, T. N. Gill, 1862 * ''Poroderma'' Andrew Smith (zoologist), A. Smith, 1838 * ''Scyliorhinus'' Henri Marie Ducrotay de Blainville, Blainville, 1816 Anatomy and appearance Scyliorhinidae catsharks may be distinguished by their elongated, cat- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovoviviparity
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that remain in the mother's body until they are ready to hatch. The young of some ovoviviparous amphibians, such as '' Limnonectes larvaepartus'', are born as larvae, and undergo further metamorphosis outside the body of the mother. Members of genera '' Nectophrynoides'' and '' Eleutherodactylus'' bear froglets, not only the hatching, but all the most conspicuous metamorphosis, being completed inside the body of the mother before birth. Among insects that depend on opportunistic exploitation of transient food sources, such as many Sarcophagidae and other carrion flies, and species such as many Calliphoridae, that rely on fresh dung, and parasitoids such as tachinid flies that depend on entering the host as soon as possible, the embryos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg Case (Chondrichthyes)
An egg case or egg capsule, often colloquially called a mermaid's purse, is the casing that surrounds the eggs of oviparous chondrichthyans. Living chondricthyans that produce egg cases include some sharks, skates and chimaeras. Egg cases typically contain one embryo, except for big skate and mottled skate egg cases, which contain up to 7 embryos. Oviparity is completely absent in the superorder Squalomorphi. Egg cases are also thought to have been produced by some extinct chondrichthyan groups, such as hybodonts and xenacanths. Description Egg cases are made of collagen protein strands, and are often described as feeling rough and leathery. Some egg cases have a fibrous material covering the outside of the egg case, thought to aid in attachment to substrate. Egg cases without a fibrous outer layer can be striated, bumpy, or smooth and glossy. With the exception of bullhead shark eggs, egg cases are typically rectangular in shape with projections, called horns, at eac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioluminescence
Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorganisms including some bioluminescent bacteria, Dinoflagellate, dinoflagellates and terrestrial arthropods such as Firefly, fireflies. In some animals, the light is bacteriogenic, produced by symbiosis, symbiotic bacteria such as those from the genus ''Vibrio''; in others, it is autogenic, produced by the animals themselves. In most cases, the principal chemical reaction in bioluminescence involves the reaction of a substrate called luciferin and an enzyme, called luciferase. Because these are generic names, luciferins and luciferases are often distinguished by the species or group, e.g. firefly luciferin or Vargulin, cypridina luciferin. In all characterized cases, the enzyme Catalysis, catalyzes the Redox, oxidation of the luciferin resultin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonic Hedgehog Protein
Sonic hedgehog protein (SHH) is a major signaling molecule of embryonic development in humans and animals, encoded by the ''SHH'' gene. This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis and the organization of the central nervous system, limbs, digits and many other parts of the body. Sonic hedgehog is a morphogen that patterns the developing embryo using a concentration gradient characterized by the French flag model. This model has a non-uniform distribution of SHH molecules which governs different cell fates according to concentration. Mutations in this gene can cause holoprosencephaly, a failure of splitting in the cerebral hemispheres, as demonstrated in an experiment using SHH knock-out mice in which the forebrain midline failed to develop and instead only a single fused telencephalic vesicle resulted. Sonic hedgehog still plays a role in differentiation, proliferation, and maintenance of adult tissues. Abn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nursehound
The nursehound (''Scyliorhinus stellaris''), also known as the large-spotted dogfish, greater spotted dogfish or bull huss, is a species of catshark, belonging to the family Scyliorhinidae, found in the northeastern Atlantic Ocean. It is generally found among rocks or algae at a depth of . Growing up to long, the nursehound has a robust body with a broad, rounded head and two dorsal fins placed far back. It shares its range with the more common and closely related small-spotted catshark (''S. canicula''), which it resembles in appearance but can be distinguished from, in having larger spots and nasal skin flaps that do not extend to the mouth. Nursehounds have nocturnal habits and generally hide inside small holes during the day, often associating with other members of its species. A benthic predator, it feeds on a range of bony fishes, smaller sharks, crustaceans, and cephalopods. Like other catsharks, the nursehound is oviparous in reproduction. Females deposit large, thick-wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
