If you thought that “cold-blooded” meant creatures like snakes, toads and crocodiles (or people you dislike), think again.

This Antarctic ice fish, formally called Chionodraco hamatus ”can withstand temperatures that freeze the blood of all other types of fish”, according to a report by the Census of Marine Life.

A special anti-freeze helps keep it alive in chill waters around the frozen continent. (This finger-length juvenile was photographed by Russ Hopcroft of the University of Alaska Fairbanks.)

The fish is among thousands of creatures found to be teeming in Antarctic and Arctic waters by the Census — an international project to map life in the oceans.

Scientists have counted 7,500 species of animals in the Antarctic and 5,500 in the Arctic — and at least 235 of them live at both ends of the earth. For a story, click here.

Scientists are trying to work out how the cold-loving creatures manage to live in both places, separated by a barrier of thousands of miles of warm waters. Polar bears, after all, only live in the Arctic while penguins are confined to the south.

Among theories are that chilly deep ocean currents carry larvae north from Antarctica. Scientists say that’s more likely than that got carried by a long-distance migrating bird or whale, or even by a ship (… few ships make such trips and only in recent years).

What do you think?