Scientists have discovered a new type of animal that can survive without oxygen. This is such an interesting discovery because this can impact a common understanding between scientists that multi-cellular life needs to live on Earth. This animal is a Jellyfish like parasite that lives in North Pacific Salmon. This 10 celled creature has evolved to the point where it doesn’t breathe at all.

Using deep sequencing approaches, the study found the H. salminicola has no mitochondrial DNA– normally containing genes for respiration–which means the parasite “lost the ability to perform aerobic cellular respiration”. This parasite is a myxozoan relative of jellyfish and corals that reportedly causes disease or cysts in the flesh of its salmon host, but is harmless to humans. A few single-cell organisms lost the ability for aerobic respiration, but never in animals.

It’s not clear how the H. saliminicola survives without oxygen, but Huchon–who led the study–said it might be taking energy from the fish. He added that the parasite’s anaerobic traits were an accidental discovery. “It is generally thought that during evolution, organisms become more complex, and that simple celled or few-celled organisms are the ancestors of complex organisms,” Huchon concluded. “But here, right before us, is an animal whose evolutionary process is the opposite.”