They are semi-terrestrial and breathe oxygen from the air through moistened gills.

Since the late 1990s the recreational use of oxygen has been promoted by oxygen bars, where customers breathe oxygen through a nasal cannula.

Larvae feed on submerged portions of aquatic plants, such as water lilies, and breathe oxygen from plant vessels.

To survive, they had to breathe oxygen from a tank with wooden mouthpieces.

Divers who breathe oxygen fractions greater than of air (21%) need to be trained in the dangers of oxygen toxicity and how to prevent them.