Wednesday, March 05, 2008

Holy Hibernating Halibut!

The 'Antarctic Cod' (Notothenia coriiceps, pictured above) became isolated from its warmer water cousins around 30 million years ago when the Antarctic circumpolar current was formed.

Scientists have discovered an Antarctic fish species that adopts a winter survival strategy similar to hibernation. Reporting this week in the journal PLoS ONE, the online journal from the Public Library of Science, scientists from British Antarctic Survey (BAS) and the University of Birmingham reveal, for the first time, that the Antarctic ‘cod’ Notothenia coriiceps effectively ‘puts itself on ice’ to survive the long Antarctic winter.

The study showed that the fish activate a seasonal ‘switch’ in ecological strategy – going from one that maximises feeding and growth in summer to another that minimises the energetic cost of living during the long, Antarctic winter. The research demonstrates that at least some fish species can enter a dormant state, similar to hibernation that is not temperature driven and presumably provides seasonal energetic benefits. Scientists already know that Antarctic fish have very low metabolic rates and blood ‘antifreeze’ proteins that allow them to live in near-freezing waters. This study demonstrates that Antarctic fish - which already live in the ‘slow lane’ with extremely low rates of growth, metabolism and swimming activity - can in fact further depress these metabolic processes in winter
tres kewl.

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