![]() The mouth is broadly curved and lacks obvious furrows at the corners. The moderately large, circular eyes are equipped with nictitating membranes (protective third eyelids). Rather heavily built, the bignose shark has a long, broad, and blunt snout with the nostrils preceded by well-developed, triangular flaps of skin. Individual sharks have been recorded traveling distances between 1,600 and 3,200 km (1,000 and 2,000 mi). ![]() In the northwestern Atlantic, the bignose shark conducts a poorly documented seasonal migration, spending summer off the US East Coast and winter in the Gulf of Mexico and the Caribbean Sea. Night-time captures of this species from close to the surface suggest it may perform a diel vertical migration, moving from deep water upwards or toward the coast at night. Young sharks may venture into water as shallow as 25 m (82 ft). The bignose shark is found near the edge of the continental shelf and over the upper continental slope, generally swimming close to the sea floor at depths of 90–430 m (300–1,410 ft). It is now common in the south-western Mediterranean Sea. It is reportedly common off Florida, the Bahamas, and the West Indies, and rare off Brazil. In the Pacific Ocean, it has been recorded from China to Australia, around Hawaii, and from the Gulf of California to Ecuador. In the Indian Ocean, it is known in South Africa and Madagascar, the Red Sea, India, and the Maldives. In the Atlantic Ocean, it occurs from Delaware Bay to Brazil, in the Mediterranean Sea, and off West Africa. Distribution and habitat The bignose shark mainly inhabits deeper water.Īccording to patchy records from around the world, the bignose shark appears to have a circumglobal distribution in tropical and subtropical waters. plumbeus), with the two forming one of the group's two branches. The bignose shark was found to be the sister species of the sandbar shark ( C. Gavin Naylor's 1992 study, based on allozyme sequences, upheld and further resolved this "ridge-backed" group. The group consists of large, triangular-toothed sharks with a ridge between the dorsal fins. Phylogenetic studies published by Jack Garrick in 1982 and Leonard Compagno in 1988, based on morphology, placed the bignose shark in the " obscurus group" of Carcharhinus, centered on the dusky shark ( C. ![]() Phylogenetic relationships of the bignose shark, based on allozyme sequences. An alternate common name for this species is Knopp's shark, originally used by Florida fishery workers since before the species was described. ![]() The type specimen is an immature female 1.3 m (4.3 ft) long, caught off Cosgrove Reef in the Florida Keys on April 2, 1947. The specific epithet altimus is derived from the Latin altus ("deep"), and refers to the shark's deepwater habits. Later authors have regarded the genus Eulamia as a synonym of Carcharhinus. Shark expert Stewart Springer described the bignose shark as Eulamia altima in a 1950 issue of the scientific journal American Museum Novitates. The various fishing pressures within its range are cause for concern given its slow reproductive rate, and it may have already declined in the northwestern Atlantic and elsewhere. It is caught incidentally by commercial fisheries in many parts of its range the meat, fins, skin, liver oil, and offal may be used. Despite its size, this shark lives too deep to pose much danger to humans. Females bear litters of three to 15 pups after a 10-month gestation period. It is viviparous, meaning the embryos are sustained to term via a placental connection. Hunting close to the sea floor, the bignose shark feeds on bony and cartilaginous fishes, and cephalopods. Its pectoral fins are long and almost straight, and there is a ridge on its back between the two dorsal fins. It has a long, broad snout with prominent nasal skin flaps, and tall, triangular upper teeth. The bignose shark is plain-colored and grows to at least 2.7–2.8 m (8.9–9.2 ft) in length. It is typically found at depths of 90–430 m (300–1,410 ft), though at night it may move towards the surface or into shallower water. Distributed worldwide in tropical and subtropical waters, this migratory shark frequents deep waters around the edges of the continental shelf. The bignose shark ( Carcharhinus altimus) is a species of requiem shark, in the family Carcharhinidae. Confirmed (dark blue) and suspected (light blue) range of the bignose shark
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