One of the more typical adaptations of apple snails is branchial respiration. The snail has a system comparable to the gills of a fish (at the right side of the snail body) to breathe under water as well as a lung (at the left side of the body) to respire air. This lung/gill combination expands the action radius of the snail in search for food. It is part of the snail's natural behaviour to leave the water when the food supply below the surface becomes inadequate.