Animal that doesn’t require oxygen! 

Scientists have just discovered that a jellyfish-like parasite doesn't have a mitochondrial genome - the first multicellular organism known to have this absence. That means it doesn't breathe; in fact, it lives its life completely free of oxygen dependency. The discovery though made by accident, isn't just changing our understanding of how life can work here on Earth - it could also have implications for the search for extraterrestrial life. We know there are adaptations that allow some organisms to thrive in low-oxygen, or hypoxic, conditions. Some single-celled organisms have evolved mitochondria-related organelles for anaerobic metabolism; but the possibility of exclusively anaerobic multicellular organisms has been the subject of some scientific debate. A team of researchers led by Dayana Yahalomi of Tel Aviv University in Israel decided to take another look at a common salmon parasite called Henneguya salminicola, and came across this discovery. It is still unclear how Henneguya Salminicola generates energy but the researchers assume that the animal is drawing it from the surrounding fish cells, or it may have a different type of respiration such as oxygen-free breathing. Fun fact What do lungs and a tennis court have in common? Their size! It seems pretty impossible, but if the lungs were opened flat they would be so big that they would cover the size of a tennis court!