Bizarre Creatures at Bottom of Arctic and Antarctic Seas

According to the Census of Marine Life, at least 235 types of cold-loving creatures have been discovered thriving at the bottom of the Arctic and Antarctic seas, puzzling scientists about how they got to both ends of the earth.

Until now, the warm tropics have been seen as a barrier keeping polar bears in the Arctic separate from penguins in the Antarctic. Only a few creatures have been known to live in both polar regions, such as long-migrating gray whales or Arctic terns.

Species living at both poles include cold-water worms, crustaceans, sea cucumbers and snail-like pteropods. They make up two percent of the 7,500 Antarctic and 5,500 Arctic animals known to date, out of a global total estimated at up to 250,000.

The findings, along with a discovery that the frigid seas teem with life, raise questions about where common polar species originated and how they wound up at both ends of the earth. Read the article to find out more.

Below: A shell-less pteropod or swimming snail, clione limacina, found in both Arctic and Antarctic waters.



Below: A bean-sized swimming snail, limacina helicina, which has crossed the tropics to live in both seas. The creature spins a mucus-net off its paddle-like foot-wings to trap algae and other small particles on which it feeds.



Below: A sand-flea hyperoche capucinus, a common predator swimming in polar waters.



Below: The nemertean pelagonemertes rollestoni has a yellow stomach that reaches out to feed all parts of the body.



Below: One of the Antarctic's ice fish, which can withstand temperatures that freeze the blood of all other types of fish.



For some previous blog posts about Antarctic and Arctic creatures see here, here, here, and here.