First multi-cellular organism which can live without oxygen discovered

Scientists have found the first animals that can survive and reproduce entirely without oxygen, deep on the floor of the Mediterranean Sea.

The team, led by Roberto Danovaro from Marche Polytechnic University in Ancona, Italy, found three new species from the Loricifera group.

One of the three new Loriciferans (so-called because of their protective layer, or lorica) has already been officially namedSpinoloricus Cinzia, after the professor's wife.

The other two, currently designated Rugiloricus and Pliciloricus, have still to be formally described.

The new species, however, don’t have the mitochondria found in almost every other animal cell, converting oxygen and nutrients into chemical energy.

Even the few parasite species once thought to be mitochondria-free seem to have had them at some point in history, and possess mitochondrial remnants that perform the same essential functions.

Instead the new Loricifera species have structures called hydrogenosomes, which are found in some single-celled organisms and require no oxygen to produce chemical energy.

The evolutionary history of these creatures is not known, but they live in an environment reminiscent of Earth’s oceans some 600 million years ago, before the deep seas were oxygenated and large animals evolved, wrote Comenius University (Slovakia) biochemist Marek Mentel and Düsseldorf University (Germany) biologist William Martin in an accompanying commentary.