In amphibians, what is the primary organ for gas exchange?

In amphibians, the primary organ for gas exchange is the skin. Amphibians are unique in that they possess both lungs and the ability to breathe through their skin, known as cutaneous respiration. This adaptation is particularly important for amphibians because many species spend part of their life cycle in water where gills are functional, while they utilize lungs when transitioning to terrestrial environments. The skin is highly vascularized, allowing for efficient gas exchange of oxygen and carbon dioxide directly with the environment, making it a crucial component of their respiratory system. Therefore, while lungs are utilized, especially in adult stages, the skin is essential for respiration throughout their life cycle, highlighting its importance as the primary organ for gas exchange.