Why Do Frogs Breathe Through Their Skin?
Frogs breathe through their skin because their thin, moist skin allows gases to pass through, supplementing their lung respiration. This process, called cutaneous respiration, is a vital part of their breathing mechanism.
The frog's skin acts like a giant lung. Its thin and permeable nature facilitates the direct diffusion of oxygen from the environment into the bloodstream and the diffusion of carbon dioxide from the blood to the outside. To maintain the skin's effectiveness, frogs must stay clean and moist. This is why they frequently secrete mucus to keep their skin hydrated. As noted by the American Museum of Natural History (https://www.amnh.org/exhibitions/frogs-a-chorus-of-colors/a-frog-s-life/thin-skin), "Like a giant lung, the thin, moist skin allows gases to pass through, helping the frog to breathe." This is further corroborated by Brown University's explanation of frog respiration (https://www.brown.edu/Departments/Engineering/Courses/En123/MuscleExp/Frog%20Respiration.htm), stating that the thin skin allows for easy diffusion of respiratory gases.
Importance of Moist Skin
Maintaining a moist skin surface is crucial for efficient cutaneous respiration. The moisture allows for the gases to dissolve and then diffuse across the skin. Dry skin significantly reduces oxygen absorption. Several sources highlight this, including the Burke Museum (https://www.burkemuseum.org/collections-and-research/biology/herpetology/all-about-amphibians/all-about-amphibians), emphasizing that amphibians, including frogs, need to keep their skin wet to absorb oxygen.
Lung Respiration vs. Cutaneous Respiration
While frogs possess lungs, cutaneous respiration plays a significant role in their overall oxygen uptake. Many sources, such as Discover Wildlife (https://www.discoverwildlife.com/animal-facts/amphibians/how-do-frogs-breathe), confirm that a substantial portion of their respiration occurs through their skin. This ability is particularly important in aquatic environments or when lung function is compromised. The Shedd Aquarium's article on amphibians vs reptiles (https://www.sheddaquarium.org/stories/amphibian-or-reptile-here-s-the-difference) also points out that many amphibians, including some frogs, utilize cutaneous respiration as a primary means of gas exchange.
