Carcharhinus obscurus (Lesueur, 1818)
Dusky shark
photo by Randall, J.E.

Family:  Carcharhinidae (Requiem sharks)
Max. size:  420 cm TL (male/unsexed); max.weight: 347 kg; max. reported age: 40 years
Environment:  reef-associated; brackish; marine; depth range 0 - 400 m, oceanodromous
Distribution:  Western Atlantic: southern Massachusetts to Florida (USA), Georges Bank, Bahamas, Cuba, northern Gulf of Mexico, Nicaragua, southern Brazil and Uruguay (Ref. 58839). Eastern Atlantic: Canary Islands, Cape Verde, Senegal, Sierra Leone. Some records from the Mediterranean and Madeira may be based on Carcharhinus galapagensis. Indo-West Pacific: Red Sea (Ref. 5485), Mozambique and South Africa to Japan, China, Viet Nam and Australia. Eastern Pacific: southern California, USA to Gulf of California and the Revillagigedo Island. Highly migratory species.
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 0-0; Anal spines: 0-0; Anal soft rays: 0-0. A large shark with a broadly rounded snout, triangular saw-edged upper teeth, curved moderate-sized pectoral fins, and an interdorsal ridge (Ref. 5578). Blue-grey, lead-grey above, white below; tips of pectoral and pelvic fins, as well as lower lobe of caudal fin and dorsal fins often dusky in young, plain in adults (Ref. 9997).
Biology:  Found in coastal and offshore waters but not oceanic (Ref. 5578). Adults are commonly found at depths of 200-400 m, young in shallower waters (Ref. 5485). A seasonal migratory species over parts of its range (Ref. 6871). Common component of the catch of the shark longline fishery (Ref.58048). Feeds on bottom and pelagic bony fish, sharks, skates, rays, cephalopods, gastropods, crustaceans, sometimes mammalian carrion and inorganic objects (Ref. 5578). Viviparous (Ref. 50449); with litter size number from 3-14 (Ref. 27549). Large adults are potentially dangerous (Ref. 4716, 6871). Utilized fresh, dried-salted, frozen and smoked for human consumption; hides for leather; fins for sharks-fin soup; and liver oil extracted for vitamins (Ref. 244).
IUCN Red List Status: Endangered (EN); Date assessed: 06 November 2018 (A2bd) Ref. (130435)
Threat to humans:  traumatogenic


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