Evolution and adaptive radiation of antarctic fishes.

There are few instances where a knowledge of the thermal physiology, habitats and lifestyles of a group of closely related species can be mapped onto a well-supported phylogeny and a detailed climatic history. The unique fish fauna of the Southern Ocean, dominated by a single group of fish whose phylogeny is known from traditional and molecular techniques, provides one such opportunity. Furthermore, these fish are living at an extreme temperature for marine organisms. Physiological and molecular studies are revealing details of the mechanisms of temperature compensation and, combined with knowledge of the thermal history, are throwing new light on the process of evolution in this unique group of fish.