Blackfin gulper shark | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Superorder: | Selachimorpha |
Order: | Squaliformes |
Family: | Centrophoridae |
Genus: | Centrophorus |
Species: | C. isodon |
Binomial name | |
Centrophorus isodon | |
Range of blackfin gulper shark (in blue) |
The blackfin gulper shark (Centrophorus isodon) is a dogfish of the family Centrophoridae in the Northwest Pacific. [2] Threats are not entirely clear but they may be bycatching from deepwater trawling and line fisheries and may also be used for cod liver oil and fish meal.
The Centrophoridae are a family of squaliform sharks. The family contains just two genera and about 15 species. They are sometimes called gulper sharks, but this is also the name of a specific species in the family, Centrophorus granulosus. These are generally deepwater fish. While some, such as the gulper shark C. granulosus, are found worldwide and fished commercially, others are uncommon and little-known. Their usual prey is other fish; some are known to feed on squid, octopus, and shrimp. Some species live on the bottom (benthic), while others are pelagic. They are ovoviviparous, with the female retaining the egg-cases in her body until they hatch.
Elasmobranchii is a subclass of Chondrichthyes or cartilaginous fish, including sharks, rays, skates, and sawfish. 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.
Shark liver oil is an oil obtained from the livers of sharks. It has been used for centuries as a folk remedy to promote the healing of wounds and as a remedy for respiratory tract and digestive system problems. It is still promoted as a dietary supplement, and additional claims have been made that it can treat other maladies such as cancer, HIV, radiation sickness, swine flu, and the common cold. To date, none of these claims has been medically validated and shark liver oil (alone) is not a medication prescribed or utilized by American physicians. However, it is a component of some moisturizing skin lotions and hemorrhoid medications.
Centrophorus is a genus of squaliform sharks. These deep-water sharks, found in temperate and tropical oceans throughout the world, are characterized by grey or brown bodies, large green eyes, and spines on both dorsal fins. These spines give them their name, from Greek κεντρον, kentron meaning "thorn" and φέρειν, pherein meaning "to bear".
The dumb gulper shark is a rare and endangered deepwater dogfish, known from only along the east coast of Australia and isolated spots north and west of New Zealand. It is also known as the dumb shark, Harrison's deep-sea dogfish, or Harrison's dogfish.
The lowfin gulper shark is a large deepwater dogfish in the family Centrophoridae.
The smallfin gulper shark is a medium-sized deepwater dogfish in the family Centrophoridae.
The leafscale gulper shark is a dogfish of the family Centrophoridae. C. squamosus is reported to have a lifespan of approximately 70 years, based on otolith ring counts. It was the first described species in the genus Centrophorus, which now contains 13 species.
The mosaic gulper shark is a small rare deepwater dogfish, found in the Pacific Ocean around Honshū, Japan and the Hawaiian Islands at depths between 260 and 728 m. It is one of 13 described species in the genus Centrophorus.
The little gulper shark is a small, deepwater dogfish of the family Centrophoridae.
The gulper shark is a long and slender dogfish usually about three feet in length generally found in deep, murky waters all around the world. It is a light grayish brown, paler ventrally, with a long snout and large greenish eyes. This deep water shark has two dorsal fins with long, grooved spines and the second dorsal fin smaller than the first. Its upper teeth are blade-like and lower have finely serrated edges. This tertiary consumer feeds on mainly fish such as bony fish, but also cephalopods such as squid and other invertebrates like crustaceans. The gulper shark is currently a vulnerable species mainly because of exploitation by humans and their abnormally long gestation period and low fecundity, preventing their population from recovering.
The finetooth shark is a species of requiem shark, in the family Carcharhinidae, found in the western Atlantic Ocean, from North Carolina to Brazil. It forms large schools in shallow, coastal waters, and migrates seasonally following warm water. A relatively small, slender-bodied shark, the finetooth shark can be identified by its needle-like teeth, dark blue-gray dorsal coloration, and long gill slits. It attains a maximum length of 1.9 m (6.2 ft). The diet of this species consists primarily of small bony fishes, in particular menhaden. Like other members of its family, it is viviparous with females giving birth to two to six pups in estuarine nursery areas every other year.
The smoothtooth blacktip shark is a species of requiem shark in the family Carcharhinidae. It is known only from the type specimen caught from the Gulf of Aden, off eastern Yemen, and a handful of additional specimens caught from the Persian Gulf, off Kuwait. Reaching 1.3 m (4.3 ft) in length, this species has a stocky greenish-colored body, a short snout, and black-tipped fins. It can be distinguished from similar species by its teeth, which are narrow, erect, and smooth-edged.
The smalltail shark is a species of requiem shark, and part of the family Carcharhinidae. It is found in the western Atlantic Ocean, from the northern Gulf of Mexico to southern Brazil. It inhabits shallow waters close to shore, particularly over muddy bottoms around estuaries. It tends to swim low in the water column and forms large aggregations segregated by sex. A slim species generally not exceeding 1.1 m (3.6 ft) in length, the smalltail shark has a rather long, pointed snout, a broad, triangular first dorsal fin, and a second dorsal fin that originates over the midpoint of the anal fin base. It is plain gray in color, without prominent markings on its fins.
The dwarf gulper shark is a dogfish of the family Centrophoridae found in the Indo-West Pacific oceans, from the Gulf of Aden, Japan, Taiwan, and northern Papua New Guinea. As a Squaliform, Centrophorus atromarginatus has high amounts of Squalene in its liver, and it is fished for this resource. It is a deep-water fish, whose habitat is in bathydemersal waters.
The Portuguese dogfish or Portuguese shark, is a species of sleeper shark of the family Somniosidae. This globally distributed species has been reported down to a depth of 3,675 m (12,057 ft), making it the deepest-living shark known. It inhabits lower continental slopes and abyssal plains, usually staying near the bottom. Stocky and dark brown in color, the Portuguese dogfish can be distinguished from similar-looking species by the small spines in front of its dorsal fins. Its dermal denticles are also unusual, resembling the scales of a bony fish. This species typically reaches 0.9–1 m (3.0–3.3 ft) in length; sharks in the Mediterranean Sea are much smaller and have distinct depth and food preferences.
The Seychelles gulper shark is a species of fish in the family Centrophoridae found in Alphonse island in Seychelles. This species is distinguished by having large tip of snout to first dorsal distance of 34% TL; first dorsal fin high ; second dorsal fin base long ; long snout ; uniformly grey with tip and the trailing edge of dorsal fins blackish. It is one of 11 described species in the genus Centrophorus.
The western gulper shark is a species of squaliform shark discovered in 2008. The species had previously been identified as a variant of the dumb gulper shark, however was differentiated based on morphology. The western gulper is known from the waters of Western Australia, as well as Indonesia, East Timor, and islands in the Southern Indian Ocean. This shark is classified as "least concern" by the IUCN.