It is microscopic, looks a bit like a jellyfish, and survives in a place that would kill every other known animal species. In 2010, at the bottom of the Mediterranean Sea, a research team found evidence of an animal able to live its entire life without oxygen.
The tiny Mediterranean animals belong to a group called the loriciferans. Loriciferans are about the size of a large amoeba. They live in muddy sediments at the bottom of the seas. But supposedly, that mud should contain some oxygen to allow the animals to breathe. The mud in the L'Atalante basin at the bottom of the Mediterranean does not.