Dusky shark - Carcharhinus obscurus


Illustration © Marc Dando

A large gray shark with a short broadly rounded snout, no markings on its fins, and it has an interdorsal ridge.

Gray to bluish gray above, white below

Males mature at about 9.1 ft [2.8 m], and reach at least 11.15 ft [3.4 m]. Females mature between 8.4 and 9.8 ft [2.57 and 3 m] and reach at least 11.9 ft [3.65 m].

Broad serrated teeth in upper jaw, narrow serrated teeth in lower jaw.

The shark is found on continental and insular shelves and oceanic water adjacent to them. It ranges from the surf zone to far out to sea, and from the surface down to 1312 ft [400 m].

Cosmopolitan in warm temperate and tropical seas.


  • Prey – Small sharks feed on bottom dwelling animals. Large specimens feed on a variety of reef and pelagic fish including sardines, tunas, eels, lizardfishes and flatfishes, smaller sharks, rays, skates, squid, octopus, cuttlefish, crabs, lobsters, starfish, barnacles, bryzoans and even whale meat and garbage.

  • Reproduction – Viviparous, with a yolk-sac placenta. Litters usually consist of 3 to 4 pups. Size at birth is 27 to 39 inches [69 to 100 cm].

The shark is migratory in temperate and subtropical areas of the northern Pacific and western north Atlantic, moving south in winter and north in summer. Young sharks form feeding aggregations.

Danger to humans – because of its size and dentition the shark is considered potentially dangerous, and it has been implicated in a number of GSAF cases. In Australia, both the dusky shark and the copper shark are referred to as bronze whalers.