Endangered
Night shark
Carcharhinus signatus
Night shark is a shark or ray in the family Carcharhinidae (order Carcharhiniformes) — Carcharhinus signatus, recorded as Endangered.
Appearance
The night shark has a slender build with an elongated, pointed snout. The eyes are large, circular, and green in life, with irregularly shaped pupils and a nictitating membrane (protective third eyelid). The five pairs of gill slits are rather short.
A slender, streamlined species, the night shark typically reaches a length of 2 m (6.6 ft).
Range and habitat
The distribution of the night shark extends along the outer continental shelves and upper continental slopes of the Atlantic Ocean, from the U.S. State of Massachusetts to Argentina in the west, among them the Gulf of Mexico and the Caribbean Sea, and from Senegal to northern Namibia in the east. Off the southeastern United States, it is usually caught at a depth range of 50–600 m (160–1,970 ft). Off northeastern Brazil, the night shark is most commonly found near the summits of seamounts ranging from 38 to 370 m (125 to 1,214 ft) deep.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
Catch records indicate that this species is usually found in schools and conducts a diel vertical migration, spending the day at a depth of 275–366 m (902–1,201 ft) and moving up to shallower than 183 m (600 ft) at night. An inhabitant of the outer continental shelf and upper continental slope, this shark most commonly occurs at depths of 50–600 m (160–1,970 ft) and conducts a diel vertical migration, spending the day in deeper water and moving into shallower waters at night.
Night sharks are quick, nocturnally active, schooling predators that feed mainly on small bony fishes and squid. Reproduction is viviparous as with the other members of its family. Females mate during the summer and give birth to litters of usually 12–18 pups after a gestation period of a year.
In crisis
Because of its low reproductive rate and historically documented declines in areas such as the Caribbean, the night shark has been assessed as vulnerable by the American Fisheries Society. A population assessment has indicated that this species is secure in the waters off the United States, but this may not be true elsewhere.
Night shark is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Night shark, Wikidata item Q525968. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
