Chapter 524: Science Friday! Entry 17- Polar Species
via National Geographic: Odd, Identical Species Found at Both Poles
February 15, 2009--Spinning a "mucus net" off its paddle-like foot-wings to trap algae and other foods, the swimming snail species Limacina helicinia is no bigger than a bean. But the discovery that it and at least 234 other species inhabit both Arctic and Antarctic waters is big news to biologists.
Finding so many species inhabiting both Poles "startled" scientists, according to a statement today from the Census of Marine Life, an international project to assess all marine life--past, present, and future--by 2010. Among the other dual-Pole species: whales, worms, and crustaceans.
Exactly where these species came from and how they ended up a world apart--with comparatively warm oceans in between--remains a mystery, the scientists said.
Up to 1.6 inches (4 centimeters) long, Clione limacina,--a shell-less pteropod, or swimming snail--preys exclusively on its "cousins": shelled pteropods such as Limacina helicinia (see previous photo).
A series of "often perilous" sea voyages in 2007 and 2008 found that this species and 234 others live on both the Arctic and Antarctica, scientists announced.
Though found worldwide, the tiny crustacean Gaetanus brevispinus is most commonly collected in polar waters, where its preferred cold-water habitat extends farther toward the surface. This copepod ("oar foot") is among 235 found to live in both Arctic and Antarctic waters
The icebreaker Polarstern cuts a path through the Antarctic waters in an undated photo. The research ship was one of several employed by Census of Marine Life expeditions during International Polar Year 2007-08.
During the "often perilous" journeys, some biologists endured 48-foot (16-meter) waves, while others collected specimens and data under armed guard in polar bear territory.
The scientists' efforts are helping to dispel the Poles' lifeless reputations.
"One hundred years ago Antarctic explorers like [Robert Falcon] Scott ... saw mostly ice," said Victoria Wadley, of the Australian Antarctic Division, in a statement. "In 2009 we see life everywhere."