What is an Amphibian?
Amphibians are vertebrate animals that have two distinct life stages – a larval stage and an adult stage. In fact, the word amphibian comes from the Greek word amphibious, meaning double life. Most amphibians lay eggs and the eggs hatch into larvae. The larvae then go through a process called metamorphosis, and they literally transform into an adult stage animal. During this time, most amphibians lose their gills and develop lungs so that they can move from water to land at will.
Frogs, toads, salamanders, newts, and caecilians are all amphibians. There are more than 6,000 species of amphibians worldwide, but unfortunately most amphibian populations are in dramatic decline, and many species are threatened or endangered.
Amphibians have skin unlike any other animals. Almost all amphibians have thin, moist skin that helps them to breath. Many scientists believe that this skin, in addition to the fact that most amphibians lay their eggs in water, causes them to be more susceptible to climatic change and pollutants. This makes amphibians an “indicator species,” meaning that the health of a particular amphibian population can help determine the health of the ecosystem in which it exists. One can think of amphibians as the “canary in the coalmine” in reference to environmental health. If amphibians go into a sharp decline, it serves as a warning to all species, including man.