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Amphibians for kids - types of amphibians

Amphibians are the class of animals that includes four types of amphibians: frogs, toads, newts, and salamanders. Amphibians first appeared on the Earth about 400 million years ago. They evolved from fishes that came out of the water and developed air-breathing lungs. Many amphibians are equally at home in fresh water and on land, but almost all amphibians breed in water. And if they live on land, it is usually near water.

Amphibians for kids - types of amphibians
Simplified structure of the amphibian body.	Above and below: representatives of the three groups of living amphibians American Meadow Frog, or Leopard Frog

Most amphibians lay eggs that float in water or are attached to stones or water plants. The way in which the larvae (the young amphibians) grow into adults is like the evolution process. A frog larva or tadpole breathes, as do fish, by means of gills. These enable the blood to take up oxygen which is dissolved in the water. The tadpole swims by using its tail, like a fish. But as it grows, it loses its fish-like character. Lungs and limbs develop until it can leave the water, climb onto the land and breathe air.

Amphibians for kids - types of amphibians
Marbled Salamander	South American Caecilian (Blindworm)

Some amphibians, such as newts, spend most of their time in the water. Others, such as frogs and toads, are at home on land and in the water, and some, like the salamanders, live mainly on land. Amphibians are cold-blooded animals and usually small in size, although the largest, the giant salamander of Japan, is six feet long. There are three main kinds of amphibians: tailed amphibians, tail-less amphibians, and caecilians.

Tailed amphibians include the newts and salamanders. Newts live mostly in water, whereas salamanders are found mainly on land. They have long tails and four short limbs, and are found all over the world except in polar regions.

Tail-less types of amphibians include frogs and toads. They have large and powerful hind limbs with which they propel themselves through water and jump about on land. They, too, are found in most regions of the world. Caecilians are legless amphibians. They live in burrows in moist soil. Some lay eggs, but others produce live young. Caecilians are found in tropical regions around the world.

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