The Biochemistry of Oxygen Transport in Red-Blooded Antarctic Fish

The temperature of the coastal antarctic waters, in which fish from temperate waters would be unable to survive, is close to the constant value of −1.87 °C, the equilibrium temperature of the ice-seawater mixture. During the increasing geographic and climatic isolation south of the Antarctic Convergence, initiated approximately 65 Ma, the physiology of antarctic fish became gradually adjusted to tolerate the progressive cooling of the environment. Because of the development of cold adaptation, the Antarctic Ocean is now the ideal habitat for the fish fauna, by virtue of the evolutionary response at different levels of life organization (organ, cell, molecule) to the many constraints of this habitat. The Convergence became a natural barrier to migration in both directions, thus representing a key factor for fish isolation and evolution.