DUSKY SHARK

Carcharhinus obscurus

Where you can see them:
Simon’s Town

DUSKY SHARK SOUTH AFRICA

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, travelling hundreds to thousands of kilometres. 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, the ridge between the first and second dorsal fins, and faintly marked fins.

A large, fairly stout shark with a rounded snout and a distinct interdorsal ridge. Unlike the sandbar, the first dorsal fin is small and its origin lies behind the axil of the pectoral fins. Similar to the bignose shark (Carcharhinus altimus) which occurs in deeper water. Usual tooth count 14/15-2-14/15 / 14-1-14

 Distribution

The adults favour deeper waters of the continental shelf between Mozambique and the southern Cape. They are attracted inshore during the annual sardine run. Juveniles are common close inshore off KwaZulu-Natal.

Reproduction

The males and females mature at 210-214 cm (19-20 years). Mating takes place offshore. Placental viviparous development; after 12 months gestation, 10-16 pups are born in winter at a length of 61-70 cm. The inshore waters of the KwaZulu-Natal coast form the nursery grounds. The maximum size of this species is 300 cm.

Feeding

The juveniles feed on cephalopods and smaller fish. As the sharks mature the diet changes to one dominated by larger fish, sharks and batoids. Sardines are important in June and July. This species often scavenges on other animals caught in the shark nets.

Behaviour

This species is regarded as dangerous, because of its large size and varied diet. The newly born juveniles may occur in packs and are commonly caught by shore anglers. This species was known by anglers as a ridgeback or slipway grey.

The likelihood of encountering a Dusky Shark when on a diving safari to South Africa?

Dusky Sharks are infrequent visitors to Aliwal Shoal and Protea Banks. When they are here, they are only seen during the winter months – May thru October. Please don’t bank on encountering a Dusky, if you do, it’s a bonus! Refer to Dive The Big 5’s Shark Timetable

Shark Time Table

Please note that the Sharks have not read this timetable so they have no idea where they are supposed to be, and when. This Timetable is purely a guide!

Remember, our daily average winter month temperature is higher that the UK average summer month temperature.