Exotic and Wildlife Medicine: Amphibian Respiration Modalities

The four modalities are branchial (gills), buccopharngeal, cutaneuous (skin) and pulmonic (lungs). Which modalities are used depends on the species, but they are all ectothermic and rely heavily on their enviroment. I will briefly go over the types but I would like to focus on the buccopharngeal form of respiration. Favored by aquatic phases or species of amphibian, the cutaneous method is sometimes supplemented. Lungs operate through pulmonary respiration. There is no diaphragm, so the animal must “swallow the air. There are many blood capillaries to gather oxygen. Partitions in the lungs exist in some to make more surface area. In free swimming larvae, they will present branchial or gill respiration and sometimes they will modify to the environment to more efficiently supply oxygen to the animal.

Buccopharngeal respiration is primarily done by aquatic species, gular or buccal pumping on terrestrial species so it depends on the primary environment. The air is pulled in through the nostrils to the nasopharnyx. The negative pressure caused through buccal expansion fills the oral cavity and nasopharnyx with air. The gular skin collapses to expel the air. Oxygen exchange is happening in the buccopharngeal capillaries where the inspiratory and expiratory breathing occurs in terrestrial amphibian lungs. Buccopharngeal breathing in amphibians is similar to some fish that gulp air.

Species that do exhibit buccopharngeal breathing are the adult salamanders, most of whom exhibit all forms of respiration. Adult frogs also breath this way. Species that do not exhibit buccopharngeal breathing are those that are fully aquatic or that remain fully aquatic their whole lives.