A recent discovery has toppled the belief that all multicellular organisms need oxygen to survive. In a first, scientists have found a jellyfish-like parasite that lacks a mitochondrial genome, which, in layman term means it doesn’t breathe.
The discovery that an organism can survive in an environment completely devoid of oxygen, not only changes human understanding of the factors that sustain life but also has implications on search for life in the cosmos.
Aerobic respiration, which was believed to be a characteristic trait of multi-cell organisms, is no longer deemed ubiquitous among animals, according to the study published in American science journal PNAS. These organisms growing in hypoxic environments gradually lost their mitochondria partially or completely and evolved into mitochondria-related organelles (MROs).
A team of researchers led by Dayana Yahalomi of Tel Aviv University had studied the common salmon parasite called Henneguya salminicola, which is a parasite that belongs to the same phylum of jellyfish, sea anemones, and corals.
"Our discovery confirms that adaptation to an anaerobic environment is not unique to single-celled eukaryotes, but has also evolved in a multicellular, parasitic animal," the researchers wrote.
A cnidarian, these parasites grow on salmon and thrive on them for their entire lifecycle, without harming the fish. Using deep sequencing and fluorescence microscopy, scientists found out that they are incapable of aerobic respiration and rely on nuclear genes that replicate mitochondria for survival.
While the researchers are yet to find out how exactly it survives, they suppose the parasites leech adenosine triphosphate from their hosts to thrive.
