Explanation:

About Henneguya salminicola

• The organism is Henneguya salminicola, a fewer-than-10-celled microscopic parasite that lives in salmon muscle. 
• The parasite does not require oxygen was discovered by accident while assembling its genome sequence. 
• One of the researchers saw that it did not have a mitochondrial genome. Mitochondria is the “powerhouse” of the cell, which captures oxygen to make energy - its absence in the H. salminicola genome indicates that the parasite does not breathe oxygen. 

How is this discovery significant?

• It significantly changes one of science’s assumptions about the animal world - that all animals use aerobic respiration and therefore, oxygen.
• It challenges evolution in organisms theory - that they become more complex as they evolve. In the case of this non-oxygen breathing organism, evolution turned it into a simpler organism that shed unnecessary genes responsible for aerobic respiration.
• Other organisms such as fungi and amoebas that are found in anaerobic environments lose the ability to breathe over time. The new study shows that the same can happen in the case of animals, too.