Antarctic cod
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{{Taxobox | color = pink | name = Antarctic toothfish, Antarctic cod | regnum = Animalia | phylum = Chordata | classis = Actinopterygii | ordo = Perciformes | familia = Nototheniidae | genus = Dissostichus | species = D. mawsoni | binomial = Dissostichus mawsoni | binomial_authority = Norman, 1937 }} The Antarctic Cod, fish of the Nototheniidae family that includes Mawson's cod (Dissostichus mawsoni), is famous for producing antifreeze protein that allows it to hide just under the Antarctic ice. With a heartbeat of once every six seconds, research involving Antarctic cod may lead to advances in cardiac medicine involving conditions where human hearts beat slowly during certain medical procedures or fail to beat fast enough due to hypothermia.
Despite its name, the Antarctic Cod is quite unrelated to the true cod; it is not even in the same order, being classified as a perciform rather than a gadiform.
These large, fish are probably mesopelagic and have been caught in waters deeper than 2000 meters. Fully grown, these grayish fish are among the biggest in the Antarctic, at least 2 meters long and weighing anywhere between 30 and 140 kilograms. The flesh is white with a high oil content. The taste is said to be similar to cod, which led to the name Antarctic Cod. Other than man, their primary enemies are the Weddell seal, the leopard seal, and Orca. They are closely related to and sometimes confused with the Patagonian toothfish.
Antarctic Cod are more commonly known as Antarctic toothfish, They are probably the main fish predator in Antarctic waters; occupying the ecological niche of sharks in more temperate seas. They are generally piscavorous but are known to eat almost anything including the remains of penguins caught by seals and orca on the surface.
Antarctic Cod have a lightweight cartilaginous skeleton, no swim bladder and fatty deposits which allow them to live in middle level waters. They also have retinas that are well adapted to the low light levels. Snow or ice on the surface of the sea, even in summer, reduces light levels to that of the great depths in the open oceans. Coloring is black to olive brown and lighter on the undersides. They have a broad head, narrow body, two fins running along the back and belly, large pectorial fins, and an additional small fin in front of the back fin. Its distribution range is generally below 65 degrees South. It is mainly caught in the Ross Sea in the austral summer. Antarctic toothfish is managed by CCAMLR the Convention for the Conservation of Antarctic Marine Living Resources. (CCAMLR) has limited fishing to a precautionary catch level in the Ross sea, fishing takes place with the aim of collecting sufficient biological and stock size information to effectively manage this fishery in the future.