Dusky shark | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Superorder: | Selachimorpha |
Order: | Carcharhiniformes |
Family: | Carcharhinidae |
Genus: | Carcharhinus |
Species: | C. obscurus |
Binomial name | |
Carcharhinus obscurus (Lesueur, 1818) |
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Confirmed (dark blue) and suspected (light blue) range of the dusky shark | |
Synonyms | |
Carcharhinus iranzae Fourmanoir, 1961 *ambiguous synonym |
Carcharhinus iranzae Fourmanoir, 1961
Carcharhinus obscurella Deng, Xiong & Zhan, 1981
Carcharias macrurus Ramsay & Ogilby, 1887
Carcharinus iranzae Fourmanoir, 1961
Galeolamna eblis Whitley, 1944
Galeolamna greyi* Owen, 1853
Prionodon obvelatus Valenciennes, 1844
Squalus obscurus Lesueur, 1818
*ambiguous synonym
The dusky shark (Carcharhinus obscurus) is a species of requiem shark, in the family Carcharhinidae, occurring in tropical and warm-temperate continental seas worldwide. A generalist apex predator, the dusky shark can be found from the coast to the outer continental shelf and adjacent pelagic waters, and has been recorded from a depth of 400 m (1,300 ft). Populations migrate seasonally towards the poles in the summer and towards the equator in the winter, traveling hundreds to thousands of kilometers. One of the largest members of its genus, the dusky shark reaches 4.2 m (14 ft) in length and 347 kg (765 lb) in weight. It has a slender, streamlined body and can be identified by its short round snout, long sickle-shaped pectoral fins, ridge between the first and second dorsal fins, and faintly marked fins.
Adult dusky sharks have a broad and varied diet, consisting mostly of bony fishes, sharks and rays, and cephalopods, but also occasionally crustaceans, sea stars, bryozoans, sea turtles, marine mammals, carrion, and garbage. This species is viviparous with a three-year reproductive cycle; females bear litters of 3–14 young after a gestation period of 22–24 months, after which there is a year of rest before they become pregnant again. Females are capable of storing sperm for long periods, as their encounters with suitable mates may be few and far between due to their nomadic lifestyle and low overall abundance. Dusky sharks are one of the slowest-growing and latest-maturing sharks, not reaching adulthood until around 20 years of age.