Mackerel icefish
Mackerel icefish captured by a trawler near Heard Island.
Photo: AFMA |
The mackerel icefish is one of a group of species exclusively found in the Southern Ocean known as 'white-blooded' fishes. These fishes survive without the red oxygen carrying pigment haemoglobin in their blood cells that other fishes have. This means their blood is colourless.
Mackerel icefish grow to 44 cm long at the Heard and McDonald Islands, and are thought to live 4-5 years.
This species is found mainly around the Heard and McDonald Islands, Īles Kerguelen and island in the south Atlantic such as South Georgia.
Mackerel icefish was once the most abundant species found near shore in waters less than 400m. Declines in population sizes in the 1970's and 1980's linked to overfishing have resulted in less icefish being available for fishing.
Icefish form schools and migrate each 24 hours from near the seafloor during the day to feed on plankton and small fish (including juvenile icefish) in midwater during the night.
They are an important food for many seabirds and seals, and also other large fish.
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