The thought of the existence of an animal that does not breathe, has probably never crossed your mind. Scientists never thought this would be possible either, because all multicellular animals on Earth whose DNA scientists have had a chance to examine have proven to have some respiratory genes. However, a new discovery of one particular multicellular organism has proved to be an exception. This accidental discovery was made when scientists were probing the genetic material of Henneguya salminicola.
H. Salminicola is a tiny parasite containing less than 10 cells that lives within the muscle tissue of salmon. The alien-tadpole-looking parasite, does not busy itself with such trifling matters as breathing oxygen. Rather, it seems to be the first multicellular animal discovered that survives without breathing.
Dorothee Huchon, a zoologist at Tel Aviv University in Israel, along with a team of international researchers examined and sequenced all of H. salminicola’s genes in their study, published in the journal Proceedings of the National Academy of Sciences on Monday.
They found that the parasite, which is closely related to jellyfish, lacks the DNA machinery necessary to “breathe” — it doesn’t have a mitochondria. The mitochondria is often called the “powerhouse” of the cell, because it uses oxygen to make energy.
Some single-celled lifeforms have the ability to survive without oxygen and do not possess mitochondria, either. Plenty of bacteria and protozoans can exist without oxygen at all, like those at the bottom of the ocean near hydrothermal vents and some human pathogens which live inside the body. Instead of oxygen, they get their energy from fermentation or use other molecules like mercury or iron.
But how H. salminicola, a multicellular organism, generates energy is still unclear. Huchon mentioned earlier, suggests it could draw oxygen from the cells in salmon or it could possess similar methods to unicellular organisms scientists have documented in the past.