The word “amphibian” is made up of two different Greek words; “amphi” which means “both” and “bios” which means “life.” So, the word amphibian means “double life.” This refers to the fact that these animals, which are vertebrates (meaning that they have a backbone) need both water and land during their life cycle. Because they are amphibians, they go through a metamorphosis (change) during which they transform from eggs to tadpoles, then to adulthood.
Tadpoles, credit Ronald T. Richards /life.nbii.gov
Amphibians lay their eggs in water, and young amphibians tend to look like small fish. 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 type of amphibian, breathing can take place in gills, lungs, the lining of the mouth, the skin, or some combination of these. An amphibian’s body temperature changes with its environment. So, in cold climates such as Idaho, amphibians hibernate during winter.
A bullfrog tadpole, credit John J. Mosesso /life.nbii.gov
Some people like to keep reptiles or amphibians as pets; however collection of these animals is regulated by the Idaho Department of Fish and Game. Click here to look at the Idaho Fish and Game web page about animal collection for additional information.