Aquatic respiration

Aquatic respiration is a biological process found amongst life forms that are aquatic or amphibious by nature. The method enables them to process oxygen from water and excrete carbion dioxide for purposes of respiration. This function is found in many speculative fiction media, particularly amongst characters who live in undersea habitats.

In comic book titles published by both Marvel Comics and DC Comics, humanoids who originate from the mythological kingdoms of Atlantis possess this trait.