Antarctic fish are acclimated to the near freezing temperatures in the southern oceans due to the development of a set of glycoproteins that prevent the fish's body processes from slowing to a crawl or stopping completely at the near zero and below zero temperatures the fish live in.
The adaptation that enables the fish that live in Antarctic oceans (collectively known as notothenioids) was an evolutionary event that spanned a large time period from 42 to 22 million years ago. Not all fish that lived in the ancient Antarctic oceans had the glycoproteins that keep them alive in cold waters but the fish that survived have all developed a set of glycoproteins that is specific to each species.
Notothenioids are the food source for the larger mammal populations of Antarctica including seals, penguins, and toothed whales. These creatures would starve if the notothenioids die out.
Oddly enough the development of a protein that protects a fish from cold environments was precipitated by a global change in environment that caused the Antarctic regions to change from a temperate region to the icy cold place it is today.
A small rapid temperature change in the Antarctic oceans could kill most species of notothenioid fish that live there according to a research led by Thomas Near, Yale associate professor of ecology and evolutionary biology, published at the Proceedings of the National Academy of Sciences web site on February 13, 2012.
Even a two degree Celsius rise in temperature over one hundred years could cause the destruction of most notothenioid species in the Antarctic because they would not be able to make a chemical adaptation to higher temperatures in so short a time frame.
Yale-affliated authors of the study are Alex Dornburg, Kristen L. Kuhn, and Jillian N. Pennington
The paper was reviewed at the Eureka Alert web site on February 13, 2012.
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