Antarctic toothfish

The Antarctic toothfish lives in the dark, near-freezing water of the Southern Ocean around Antarctica, including the Ross Sea. It is the largest bony fish in that ocean. Fully grown ones can pass 1.7 metres and 135 kilograms, about twice as big as the next-largest Antarctic fish. It has a big head, a wide mouth and two rows of teeth in its upper jaw.

Its blood contains antifreeze proteins, so it does not freeze even in water colder than 0 degrees Celsius. It hunts smaller fish and crustaceans, and orcas, other toothed whales and seals hunt it in turn. People catch it too, and it is sold in shops together with a close relative under the name Chilean sea bass.

Why is it called a toothfish?

The name comes from the two rows of teeth in its upper jaw, which give it a bit of a shark-like look. Its scientific name Dissostichus means 'two lines' in Greek and refers to two long lateral lines along its body, which help it sense prey. The species name honours the Australian geologist Douglas Mawson, who led an expedition along the Antarctic coast from 1911 to 1914.

A big eater in the cold

Out in the open ocean, big fish eat little fish more or less whatever they are, and the toothfish is a hungry hunter of smaller fish. It was first officially described in 1937 by the English fish scientist John Roxborough Norman, from a specimen found off MacRobertson Land. It is often wrongly called 'Antarctic cod', but it belongs to a different fish family, the Nototheniidae.

On the globe

The model shows a big-headed, wide-mouthed fish of the cold deep sea, as the card describes. Look for its large jaw.