Latin name

Notothenia coriiceps

Other name

Antarctic yellowbelly rockcod, or Antarctic bullhead notothen.

Identification

Notothenia: Greek, 'notos', ou; νοτος, ου), from the south + Greek, 'e 'eutheneia',as or 'euthenia', as (ευθενεια, ας; ευθενια, ας), abundance;  coriiceps: coriiceps from Latin corium skin or leather plus ceps head = skin head or leatherhead.

Black rockfish are characterised by a wide interorbital space, fewer thoracic rays and the absence of scales under the eye. The teeth consist of a multi-row dental plate, are fang-shaped and are located in the outer part of the jaw. They lack a swim bladder. Bone density increases during adulthood, resulting in reduced buoyancy and a transition from pelagic to bottom swimming. Adults of N. coriiceps have a dense, well-developed skeleton compared to their congener Notothenia rossii, which explains their lower buoyancy. Their epithelium is characterised by the presence of fat droplets, which serve as a mechanism for the accumulation of dietary lipids. Fat droplets also accumulate in bone tissue.

Features of fish fins

Dorsal spines (total): 4 - 6; Dorsal soft rays (total): 35 - 38; Anal soft rays: 26 - 30.

Fish colouring

Members of this genus have scales that are usually brown or grey in colour.  

Distribution

Black rockcod maintain a circum-Antarctic distribution, probably determined at least in part by the presence of the Antarctic Circumpolar Current (ACC) and by the peculiarities of egg distribution. Populations of this species have been recorded in the western Ross Sea, the Weddell Sea, the West Antarctic Peninsula, the Scottish Arc Islands to South Georgia, the Balleny Islands and the sub-Antarctic islands of the Indian Ocean.

Habitat

Bottom-dwelling polar fish species that range in depth from 0 to 550 metres. Most are found at depths of less than 200 metres.

Size

Adult males usually reach a length of about 50 centimetres (20 inches). And their maximum length is 62 centimetres.

Behavior

Like most other Antarctic fish, N. coriiceps possesses a number of adaptations that optimise the organism's vital activity at sub-zero temperatures. These include a modified response to heat shock, the production of antifreeze glycoproteins that prevent body fluids from crystallising as ice at sub-zero temperatures, and an abundance of polyunsaturated fatty acids that allow cells to maintain membrane fluidity. Black rockfish have a limited tolerance to sudden changes in temperature, but have shown the ability to extend their temperature limits when acclimatised to higher temperatures for prolonged periods.

Food and feeding habits

Black rockcod feed on macroalgae, amphipods and euphausiids. They appear to feed all year round, although the composition of their diet is likely to vary with the seasons.

Reproduction

Specimens of this species mature slowly, at around 4 or 5 years of age, due to low water temperatures. To spawn, they emerge from the depths closer to shore and incubate their eggs in the water. The current often carries the eggs to warmer areas of the ocean. The young fish emerge in 14 to 20 days. They spend the first few years of their lives close to shore and move into deeper water when they are 3-5 years old. The higher the water temperature, the faster the fish grow. These fish can live up to 10 years.

Fishing

Of potential interest. Black rockfish are not currently fished commercially.

Relationship with a person

Harmless.