[3] The earliest known notothenioids are the fossils Proeleginops and Mesetaichthys from the Eocene La Meseta Formation of Seymour Island, the latter of which already shows close similarities with the extant Dissostichus.

[5] These unique environmental conditions in concert with the key evolutionary innovation of Antifreeze glycoprotein promoted widespread radiation within the suborder, leading to the rapid development of new species.

[3] However, a depth-related diversification has given rise to some species attaining increased buoyancy, using lipid deposits in tissues and reduced ossification of bony structures.

[3] This reduced ossification of the skeleton (observed in some notothenioids) changes the weight and creates neutral buoyancy in the water, where the fish neither sinks nor floats, and can thus adjust its depth with ease.

[3] Notothenioids have a variety of physiological and biochemical adaptations that either permit survival in, or are possible only because of, the generally cold, stable seawater temperatures of the Southern Ocean.

[14] Many notothenioid fishes are able to survive in the freezing, ice-laden waters of the Southern Ocean because of the presence of an antifreeze glycoprotein in blood and body fluids.

[17] Notothenioidei was first described as a separate grouping, as a "division" he named Nototheniiformes, by the British ichthyologist Charles Tate Regan in 1913.,[1] this subsequently has been considered as a suborder of the Percifomes.