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.

This lack of haemoglobin results in an oxygen-carrying capacity in icefishes that is less than 10% of that seen in closely related red-blooded species. Therefore, nearly all icefishes are living only in the cold-stable and oxygen-rich environment of the Antarctic.

Mackerel Icefish also do not produce the related myoglobin proteins in their muscles and, like many related Polar fishes, carry compounds in their blood that prevents it from freezing.

« »