Extremophile Fishes pp 35-57
The Adaptive Radiation of Notothenioid Fishes in the Waters of Antarctica
Fishes of the perciform suborder Notothenioidei, which dominate the ichthyofauna in the freezing waters surrounding the Antarctic continent, represent one of the prime examples of adaptive radiation in a marine environment. Driven by unique adaptations, such as antifreeze glycoproteins that lower their internal freezing point, notothenioids have not only managed to adapt to sub-zero temperatures and the presence of sea ice, but also diversified into over 130 species. We here review the current knowledge about the most prominent notothenioid characteristics, how these evolved during the evolutionary history of the suborder, how they compare between Antarctic and non-Antarctic groups of notothenioids, and how they could relate to speciation processes.