By Michael Le Page
Fluorescent dye highlighting nuclei and membranes in a parasite that uses no oxygenImage courtesy of Stephen Douglas AtkinsonBreathing oxygen is seen as a fundamental characteristic of multicellular animals, but we have found at least one that can’t do it.
“It has lost the ability to breathe oxygen,” says Dorothee Huchon at Tel Aviv University in Israel. It remains a mystery how this animal, a parasite that infects salmon, gets the energy it needs without oxygen, she says, but it probably steals it from its host.
All plants and animals were thought to use oxygen to generate a fuel called adenosine triphosphate (ATP), which powers cellular processes. The generation of ATP from oxygen takes places in structures called mitochondria.