First, body shape
Frog tadpoles have a round body, a long, oval tail and a short tail, and are the larvae of toads.
Second, color.
Their tadpoles are also different in color. Frog tadpoles are shallow, but their bodies and tails are uniform in color. Toad tadpoles are dark and black, but their tails are lighter than their bodies.
Third, the position of the mouth.
The mouth of the frog tadpole is in front of its front end. Toad tadpoles have their mouths facing down, close to the abdomen.
Extended data
Development process of tadpoles
Early tadpoles were round or oval, fish-like and had lateral organs. Because there are no pores in the mouth, you can't eat; After that, eyes and nostrils appeared 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.
The tail is large and flat, with segmented caudal muscles inside, and thin-film upper and lower caudal fins above and below the sarcomere, which can help tadpoles swim in the water.
After the mouth appeared, I scraped off the seaweed with the horny teeth of my lips and began to live independently in the water. When the sucker disappears, the outer gill will also shrink; With the healing of pharyngeal skin folds and body wall, gill cover is formed, and 1 outlet hole is left on the left side of body surface or in the middle or back of ventral surface. Internal gill breathing in gill cavity can also breathe free oxygen on the water surface with the occurrence of lung.
After a certain period of development, some first grow hind limbs, the end of which differentiates into five toes, and then grow forelimbs from the gill cover, such as frogs.
Some grow forelimbs first and then hind limbs, such as salamanders. With the tail gradually shrinking, the mouth also changed obviously, and gradually developed into a young man who can live on land.
Baidu Encyclopedia-Tadpoles (larvae of frogs and toads)