How Do Animals Breathe Underwater?

The manner in which animals breathe while underwater depends on a variety of factors like size for example and varies accordingly. Most fish breathe through gills.

An animal that is not very active is able to breathe through its skin, very similar to how earthworms breathe on land. An extremely active animal will not receive adequate oxygen simply by breathing through its skin. This is because when an animal is very active its muscles require a higher quantity of oxygen to function well. If the animal has a large body then more oxygen can be absorbed. Its skin can be extended by sticking out of its body in the form of folds and projections. If these projections get a blood supply then a gill is formed. This gill is referred to as an external gill because it is in the exterior of the animal. Other types of gills include the tracheal gill and internal gills.

Grills