Tadpole is the larva of amphibians such as frog, toad, Newt, etc. the newly hatched tadpole has a spindle shaped body without limbs, mouth and inner gills. It has a long lateral tail and branched outer gills on both sides of its head. It is absorbed on aquatic plants and fed by the residual yolk in the body.
Tadpole is a primary stage of amphibian ontogeny. In the early stage, tadpoles are round or oval in shape and have lateral line organs. Since there is no pore in the mouth, food can not be absorbed; after the eyes and nostrils appear one after another; there is a sucker under the head, which can be used to adsorb on aquatic plants. There are external gills on both sides of the head, which have respiratory function.