First Oxygen-Free Animal Discovered

It has been common knowledge that only viruses and single-celled microbes can live without oxygen long-term. However, research teams recently discovered 3 new species of multicellular animals that lived normally in the oxygen-free depths of the Mediterranean Sea.

Team leader Roberto Danovaro said in a statement, "Our results indicate that the animals we recovered were alive. Some, in fact, also contained eggs." The animals shown in the image above resemble tiny jellyfish - each measuring less than a millimeter across - and somehow the manage to thrive in the extremely salty seafloor environment. The findings of their research was published in the April 6th issue of BMC Biology.

Humans and most other organisms use structures called mitochondria which uses oxygen to convert nutrients into energy molecules (ATP). These new creatures have modified mitochondria called hydrogenosomes that can produce ATP without using oxygen.

The study also "has strong implications for the search for life in the universe," said Abel Mendez, an astrobiologist at the University of Puerto Rico at Arecibo. Perhaps Europa, one of Jupiter's icy moons might have a subsurface ocean of cold, salty, oxygen-free environments, similar to that where these animals were discovered.