Global environmental challenges
******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?