Loricifera, life without oxygen. Picture: Roberto Danovaro, Antonio Dell’Anno et al.
Scientists have discovered multicellular organisms in the Mediterranean that can live entirely without oxygen
Scientists have discovered the first multicellular organisms that can live and reproduce entirely without oxygen. What does not sound particularly exciting is nevertheless a sensation.
The Italian and Danish scientists who found the three species Spinoloricus, Rugiloricus and Pliciloricus from the Loricifera group in the Mediterranean Sea near Greece at a depth of 3000 m in an anoxic sediment were thus able to show that not only did organisms that do not depend on oxygen evolve on Earth, but that oxygen ultimately did not have to be present for the development of multicellular organisms on other planets.
The creatures not only manage without oxygen, they are also otherwise hardy, as the scientists write in their article for the journal BMC Biology. The sediment in which they live at coarse depths contains not only a great deal of salt, but also toxic hydrogen sulfide gas.
Thus, if not only unicellular organisms but also multicellular organisms can exist in an oxygen-free environment, it is conceivable that more complex organisms could have evolved on other planets in an evolutionary lineage that differs significantly from terrestrial life. Until now, it was amed that only viruses, bacteria or archaea could exist in such conditions. Multicellular organisms can live only temporarily without oxygen.
The newly discovered organisms are also different from other multicellular organisms. Thus, they have no mitochondria, which are found in virtually all eukaryotes’ cells and serve as energy suppliers. Through cellular respiration by means of oxygen, they produce ATP, which is the energy for each cell. Instead, they have hydrogenosomes as organelles that can produce ATP even under anaerobic conditions and are found, for example, in protozoa such as ciliates.