Cutaneous respiration occurs in insects and organisms that do not have respiratory organs. These organisms diffuse dissolved oxygen across their bodies in order to breathe.
In insects that breathe through cutaneous respiration, the dissolved oxygen in the air diffuses across their cuticle into a closed tracheal system. The air can then go through the trachea and provide air and nutrients to the insect. Cutaneous respiration can be used as the sole means of breathing or to simply diffuse gases across their cellular membranes. It occurs in a wide variety of organisms including insects, amphibians, sea snakes and turtles and with some fish.