Spotted ragged-tooth shark

IDENTIFYING FEATURES

The upper surface of this robust fish is silver to grey and the belly is white. There is a distinct black spot on the gill covers and the anal and dorsal fins have white tips.

Ragged-tooth shark. Photo courtesy of V Smith, UK

Scientific Name: Caranx sexfasciatus
Common Name: sand tiger shark (USA), grey nurse shark (Australia)
Family: Lamnidae
Size: Can grow to 4,3 metres and weigh up to 294kg

DISTRIBUTION

In the Eastern Cape the young often enter estuaries where there are fewer predators and an abundance of food. In late winter adults move up the coast to KwaZulu-Natal where they mate.

HABITAT

Ragged-tooth sharks generally occur in shallow coastal waters on or near rocky reefs.

DIET

They feed almost exclusively on fish. The smooth-edged, sharp pointed teeth are designed for catching a variety of fish and juveniles of other sharks, which are usually swallowed whole. Ragged-tooth sharks may feed co-operatively in packs on shoaling fish. They are ambush predators and are usually more active at night. These animals do not feed very often during their gestation period.

REPRODUCTION

Mature females in South African waters are believed to reproduce only once every two years. The adults move from the Eastern Cape to KwaZulu -Natal in July where they congregate on reefs such as Protea Banks and Aliwal Shoal to mate. Courtship is a lengthy process which involves the males inflicting bites on the females as they hold on during mating. Many pregnant females then migrate further north to the St Lucia Marine Reserve in the Isimangaliso Wetland Park for part of their gestation period, which is between 9 and 12 months. 

Ragged-tooth male sharks only reach sexual maturity at seven years and females at 10 years. The young develop in the uterus with energy supplied by large egg yolks. The largest embryos feed on the other developing embryos within the uterus and usually only two pups are born, one pup per uterus. The females return to the south-eastern Cape waters to pup.

CAPTURE

Ragged-tooth sharks are caught by shore anglers particularly during fishing competitions and are sometimes taken by ski-boat anglers. Large numbers of these sharks have been tagged and released alive by anglers, contributing to data on movement and growth. They also form part of the by-catch of commercial line-fishers and trawlers. Ragged-tooth sharks are important for dive eco-tourism in South Africa and Australia.

REGULATIONS

Daily bag limit: 1 per person per day
Minimum size limit: none
Closed season: none
Other regulations: no sale, recreational species
The St Lucia Marine Reserve provides protection for pregnant females

STOCK STATUS

World-wide this species is considered to be vulnerable to over-exploitation due to late maturity and particularly small litters. However, the species is listed as critically endangered in New South Wales, Australia.

Downloadable fact sheet

 

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