Scientists have just discovered the first multicellular animals that can survive entirely without oxygen. They live in the L'Atalante Basin in the Mediterranean Ocean, a place with salt brine so thick it doesn't mix with oxygen-containing waters above.
This is pretty crazy stuff. Previously, it was thought that only single-celled life could exist in such inhospitable places, but this proves otherwise.
The animals took up radioactively tagged leucine (an amino acid), and a fluorescent probe that labels living cells, evidence that they were alive when they were collected. The researchers also found examples of individuals that contained eggs and evidence of apparent molting, which led them to conclude that the animals spend their whole lives in the harsh sediments. The creature's cells apparently lack mitochondria, the organelles that use oxygen to power a cell. Instead they are rich in what seem to be hydrogenosomes, organelles that can do a similar job in anaerobic (or oxygen free) environments.
This is interesting not only for the study of our oceans, but for life off our planet as well. After all, if life can exist where there's no oxygen, what's to say life can't exist in some of the harsher atmospheres that exist on other planets and moons? And at this point, why the hell haven't they contacted us yet? Are we not ready? Just tell us what to do, space friends! Come on! [Science Mag via Slashdot]