How do frogs breathe through their skin?

Frogs breathe through their skin via a process known as cutaneous respiration. This is possible because their skin is thin, moist, and well-supplied with a dense network of blood vessels, which allows for the efficient diffusion of oxygen and carbon dioxide between the animal and its environment.123

The skin serves as a vital respiratory surface throughout a frog's life, though its importance varies by species, habitat, and environmental conditions. For example:13

• Aquatic vs. Terrestrial: Aquatic frogs often rely more heavily on skin respiration, while terrestrial species may depend more on their lungs.13
• Hibernation: During winter, when metabolic rates drop, frogs can meet their entire respiratory needs through their skin while submerged in water or buried in moist soil.13
• Gas Exchange: While lungs are used for oxygen uptake, the skin remains a primary route for the elimination of carbon dioxide in most frogs.13

This flexibility in gas exchange is a hallmark of amphibian physiology, allowing them to adapt to diverse environments.23