Антарктика балықтары тұқымдасы

Family of fishes
In some scientific literature, the term "cod icefish" is used to identify members of this family. This should not be confused with the term "icefish," which refers to the "white blooded" fishes of the family Channichthyidae. See Icefish (disambiguation). Nototheniidae, the notothens or cod icefishes, is a family of ray finned fishes, part of the suborder Notothenioidei which is traditionally placed within the order Perciformes. They are largely found in the Southern Ocean.

Nototheniidae was described as a family in 1861 by the German born British ichthyologist Albert Günther with the type genus being Notothenia which had been described in 1844 by Sir John Richardson with the species Notothenia coriiceps which Richardson had also described in 1844 subsequently being designated as the type in 1862 by Theodore Nicholas Gill. They are traditionally placed in the order Perciformes together with their relatives, Actual phylogenetic relationships among species of suborder Notothenioidei have not yet been determined with certainty.

Nototheniidae species have no swim bladder, however, they have other depth related adaptations, such as increased fatty tissues and reduced mineralization of the bones, resulting in a body density approaching neutral, to fill a variety of niches. As the chilly Antarctic and sub Antarctic waters of the Southern Ocean average , most species of these regions produce antifreeze glycoproteins to prevent the formation of ice crystals in blood and other body fluids. The concentration of antifreeze glycoproteins can vary with differing environmental conditions, such as colder environments caused by location. Larger amounts of the proteins have been found in species with habitats in higher latitudes, due to the higher expression of the protein and longer degradation time compared to relatives in more temperate regions, portraying flexible temperature regulation. Some species exhibit polymorphism, for example, the circum Antarctic Trematomus newnesi exists as two morphs in the Ross Sea, the typical morph and a large mouthed/broad headed morph.

Nototheniidae species are the major fish resource in the Southern Ocean, many notothens are under increasing pressure from commercial fishing, particularly the Patagonian toothfish and the Antarctic toothfish.