Until now, it had generally been assumed that all animals breathe oxygen. According to Israeli scientists, however, that isn’t the case – they’ve announced that a tiny relative of jellyfish and corals manages to get by without. The discovery was initially made by Tel Aviv University’s Prof. Dorothee Huchon, when she realized that a microscopic fish parasite known as Henneguya salminicola lacked a mitochondrial genome. Found in large numbers in most cells, the mitochondria are organelles that capture oxygen in order to produce energy. Because these are lacking in the parasite, Huchon and colleagues determined that it must not be an oxygen-breather. While organisms such as fungi and amoebas also don’t breathe oxygen, this is reportedly the first time that it’s been noted in an actual animal – Henneguya does in fact qualify as an animal, even though it’s made up of fewer than 10 cells.