All About Amphibians

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Informative video with everything you need to know about amphibians. Head to ngscience.com for full range of related content including worksheets, interactive resources and ebooks.

The word amphibian comes from a Greek term which means ‘double life’. This is due to their unique life cycle which, for many amphibians, begins in water and moves on to land. Amphibians reproduce sexually by external fertilization, and hatch from eggs.

There are three main groups of amphibians. Frogs are amphibians we are most familiar with. They often have short bodies with powerful hind legs for moving about on land and in water. Toads are similar in appearance to frogs, but often have drier and rougher skin.

Salamanders are amphibians that are similar in appearance to lizards. They have long, slender bodies with a tail. Caecilians are limbless, worm-like amphibians. Most live underground.

Most amphibians get the oxygen they need using lungs to breathe in air. Many amphibians are also able to take in oxygen through their moist skin.

The life cycle of a frog is different from other vertebrate animal life cycles in that the young do not look like their parents. As they grow and develop, their bodies change form. This change in body form is called metamorphosis.

Frog eggs are usually laid in water with many eggs usually laid at one time. A frog larva, called a tadpole, hatches from each egg. A tadpole does not look like a frog. It has a tail to help it swim and uses gills to take in oxygen.

As a tadpole grows and develops, it starts to look more like a frog. Its tail gets smaller and it begins to develop legs and feet. Its gills develop into lungs as it prepares to move onto land. As a frog grows, it moves from life in water to life mostly on land.