Grey Nurse (Sand Tiger Shark)

Carcharius taurus
Image by Jeff Kubina.

The grey nurse shark is a large shark inhabiting coastal waters worldwide, with many different names in different countries in the world.

Despite a fearsome appearance and strong swimming abilities, it is a relatively placid and slow moving animal. It is considered not aggressive unless provoked. The body is stout with two large dorsal fins and the tail is elongated with a long upper lobe. It grows to a length of 3.2 metres. This shark weighs 90 to 160kg. The grey nurse shark usually has a grey back and white underside.

Their diet consists of bony fishes including mackerels, rays, squids, crabs, lobsters and even other sharks. The sharks typically congregate in coastal waters. Often they will shelter in caves or gutters during the day and come out at night to feed. During the day they exhibit sluggish behaviour becoming more active during the night.

The grey nurse shark is the only known shark to gulp and store air in its stomach in order to maintain neutral buoyancy while swimming.

The species bear live young from eggs which hatch inside the uterus (of which the female have two). Inside the uterus, the young sharks develop then eat each other until there are only two young left, one in each of the uteri. To provide further nourishment for her young, the mother continues to produce eggs that are eaten by her two remaining young. After two years the young are around 1m long, miniature replicas of their mother and fully able to fend for themselves.

This fascinating animal is listed as vulnerable on the IUCN Red List and as endangered under Queensland’s Nature Conservation Act 1992.