Interesting Facts:
Icefish live in deep, cold water.  They are found closest to Heard and McDonald Islands, which are approximately 4000km southwest of Perth, which is the same distance as Sydney is from Perth, so it is a long way for boats to go and catch icefish.  They are also found in other sub-Antarctic waters such as Bouvet Island and other islands of the Scotia Arc as well as the northern part of the Antarctic Peninsula.   Icefish are pelagic, which means that they are found constantly swimming in the mid-water column.  They can be found in water up to 700m deep but most of the fish are caught in water around 350m deep.

Icefish live in very cold waters where the temperature is only 1-2^oC (Your fridge at home is usually around 4^oC).  They have special chemicals in their blood that stop the cold water freezing in their bodies.  Scientists are looking at their blood to see if they can use this amazing ability in other useful situations such as allowing frozen foods to be kept longer and keeping organs cool for human transplants.  Icefish also have colourless blood, because their blood doesn’t contain any iron, the substance in haemoglobin that makes our blood red.

There is not very much current information about icefish.  Commercial fishers are helping scientists with their research, but as the commercial fishery is still only in a development phase it is still quite small.

Another interesting point is that the USA Navy named one of their submarines the USS Icefish.  This vessel was stationed at Fremantle, WA during the Second World War.

Other names:
Icefish (Champsocephalus gunnari) is also known as mackerel icefish.  They might be confused with the Patagonian toothfish.  Toothfish live in the same places as icefish but they are not the same species.

What they look like:
The icefish got its name because it has little pigmentation and a glassy appearance.  Icefish live in the same area as Patagonian toothfish (Dissostichus eleginoides) although the two species look quite different.  The bodies of icefish are leaner and not as deep as those of toothfish.  The toothfish has a larger, more rounded head whereas the icefish is streamlined.  The icefish has an easily recognisable fin structure as it looks as if someone has pinched them in the middle.

They are ray-finned fish; this means that they have a strong line of cartilage in their fins which works like a mast holding up the sails.  The rays give the fish more control over its movements and help it to become more streamlined in the water.

Icefish take a long time to grow because the cold conditions slow their growth.  They reach a maximum length of 60cm and live for about 15 years.  They are mature adults when they are 22-26cm long and about 3-4 years old.

Heard Island

Where they are found:
Icefish are found in deep, cold water and they love to cruise around close to Antarctica.  They are found in the oceans surrounding Antarctica including the Southern Ocean and southern parts of the Atlantic and Indian Oceans.  They are on the list of species caught as part of the Heard and McDonald Island Managed Fishery which occurs in Australian waters.  This fishery is managed by the federal government by the Australian Fisheries Management Authority (AFMA).

What they eat:
Icefish are carnivores so the major part of their diet is small swimming prawn-like crustaceans such as krill and mysids.  They also eat microscopic animals called zooplankton that occur in blooms within the open ocean.  Icefish are an important food source to other larger sub-Antarctic fish, seals and sea lions.