Dusky shark
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| Carcharhinus obscurus (Lesueur, 1818) |
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 Range of dusky shark
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The dusky shark, Carcharhinus obscurus, is one of the larger species of shark, reaching 350 kg. The dusky shark is also known as the black whaler and dusky whaler. Less frequently used names include bay-shark, brown dusky shark, brown shark, common whaler, dusky ground shark.
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[edit] Physical description
The dusky shark has a long streamlined body that is brown or gray above and white below. On the side of the body a stripe can be seen from the pelvic fins to the head. They can reach 3.65 m.
[edit] Diet
The diet of the dusky shark includes small schooling fish such as sardines and anchovies, as well as larger fish like tuna, mackerel, flatfish and eels. The dusky shark also eats dogfish, catsharks, skates and rays and sometimes bottlenose dolphins.
[edit] Reproduction
Females become sexually mature at about 3 m (10 ft), while males become sexually mature at 2.9 m (9.5 ft). They are viviparous and females give birth to a litter of 6 to 14 pups. After 16 months gestation the pups are delivered at a size of approximately 95 cm (3 feet).
[edit] Habitat
The dusky shark is found worldwide in warm temperate continental waters extending from the surface down to a maximum depth of 400 m. Juveniles are often seen by scuba divers at Fairy Bower, near Shelly Beach, in the Sydney suburb of Manly.
[edit] Similar species
Sandbar sharks, and bignose sharks have higher first dorsal fins originating farther forward. The dusky shark is hardest to distinguish from the sandbar shark which has a smaller maximum size. Bignose sharks have longer snouts. The silky shark has the second dorsal fin with free tip length usually more than twice fin height. The night shark has green eyes. Bull sharks and spinner sharks lack interdorsal ridges.
[edit] Danger to humans
The dusky shark has not been linked to many attacks although it is considered potentially harmful. This is due in large part to its imposing size and propensity to dwell in shallow coastal waters.
[edit] References
- Shark Specialist Group (2000). Carcharhinus obscurus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 09 May 2006. Database entry includes justification for why this species is near threatened
- "Carcharhinus obscurus". FishBase. Ed. Ranier Froese and Daniel Pauly. November 2005 version. N.p.: FishBase, 2005.
- Carcharhinus obscurus (TSN 160268). Integrated Taxonomic Information System. Accessed on 30 January 2006.
[edit] External links
