Danish an italian researchers have found a complex lifeform that does not breathe oxygen, in a deep sulfurbassin in Greece. This finding may have great impact on oursearch for lifeforms on other celestial bodies.

During the last ten years three oceanographic expeditions were conducted to search for the presence of living fauna in the sediments of the deep anoxic hypersaline L'Atalante basin (Mediterranean Sea).

The researchers report that the sediments of the L'Atalante basin are inhabited by three species of the animal phylum Loricifera (Spinoloricus nov. sp., Rugiloricus nov. sp. and Pliciloricus nov. sp.) new to science.

The authors provide evidence that these organisms are metabolically active and show specific adaptations to the extreme conditions of the deep basin, such as the lack of mitochondria, and a large number of hydrogenosome-like organelles, associated with endosymbiotic prokaryotes.

This basically means that they - instead of breathing Oxygen - uses Hydrogen, retrieved from seawater and sulfor-dioxide.

They are working on two possible theories: Either it is a remaint lifeform from prehistoric Earth where oxygen was sparse, or it is an example of extreme adaption to hostile environments

This is the first evidence of a metazoan life cycle that is spent entirely in permanently anoxic sediments. Their findings allow us also to conclude that these metazoans live under anoxic conditions through an obligate anaerobic metabolism that is similar to that demonstrated so far only for unicellular eukaryotes.

The discovery of these life forms opens new perspectives for the study of metazoan life in habitats lacking molecular oxygen, such as the Saturn moon Europa

Source: Copenhagen University