Vertebrates: Amphibians

The word 'amphibian' is derived from the Greek word 'amphibios', which means a double life. The amphibians include the animals that live in the water as well as on the land. They start their life underwater and move on the land in their adulthood.

 

Amphibians live in various environments. However, most species of amphibians require freshwater habitats such as swamps, ponds, streams or wet environment for breeding. Some of the frog species rely on the pools of water that is collected in the cup-shaped bases of plants or tree hollows.

All amphibians begin their life in water with gills and tails.  As they grow, they develop lungs and legs for their life on land. The tadpole, or newborn frog, is born and lives in water. It has a tail that allows it to swim like a fish. It also has gills so that it can breathe under water. As the tadpole grows into a frog, it loses its gills and tail, and develops legs for moving on land. Most amphibians can both walk and swim in water.

Depending on the species of amphibian, breathing can take place in gills, lungs, the lining of the mouth, the skin, or some combination of these.

Amphibians are cold-blooded, which means that they are the same temperature as the air or water around them. In cold climates, amphibians hibernate during the winter.

There are more than 4,000 different kinds of amphibians. Members of this animal class are frogs, toads, salamanders, newts, and caecilians or blindworms.