A cold - blooded, smooth - skinned vertebrate of the class Amphibia, such as a frog or salamander, that characteristically hatches as an aquatic larva with gills.The larva then transforms into an adult having air - breathing lungs.

• 两栖动物一种两栖纲的皮肤光滑的冷血脊椎动物，如蛙或蝾螈，此类动物的特征是有鳃的幼虫在水中孵化，然后逐渐转变成用肺呼吸的成虫