Amphibians are in the class of vertebrates called “Amphibia”, which includes frogs, toads, salamanders, newts and caecilians. The characterization of amphibians (verses other vertebrates) is that amphibian eggs and larvae live primarily in water and amphibian adults live primarily on land. (There are a few species of amphibians, however, that do not match this characterization because the species neither lives in water as young nor lays eggs.)
Amphibians have “naked” bodies without hair, scales, or feathers, with the exception being some caecilians that have very small scales on their segmented bodies.
Frogs and toads belong to an order of amphibians called Anura. Frogs are tailless amphibians that have moist and smooth skin, long hind legs and short front legs, tiny teeth, and webbed feet. The name “toad” is a non-scientific name for frogs that lack teeth and have dry, rough skin and have shorter hind legs when compared to frogs. Frogs and toads can be found almost anywhere in the world and in any color of the rainbow.
Salamanders and newts belong to an order of amphibians called Caudata and (much like frogs) widely vary in color. Most caudates live in the Northern Hemisphere, but a few live in the northern part of the Southern Hemisphere in South America. Salamanders have soft, wet skin, four legs of similar length, and tails that are longer than their main bodies. “Newt” is the non-scientific name for the smaller salamanders. Salamanders are often called “sallies” by people who raise them or keep them as pets.
Caecilians belong to an order of amphibians called Gymnophiona. Caecilians are long, segmented amphibians that externally resemble earth worms. These worm-like creatures have bones, however, and their skull is particularly suited for borrowing in the ground. These amphibians live primarily in tropical areas and are the least studied and the least well-known of all amphibians.
Because amphibians live in such a varied range of habitats, they have developed varied means of self-defense. The most common means of self-defense among amphibians is the production of toxic or nasty tasting skin excretions. These excretions (which range from simple skin moistening to spraying) aid in incapacitating and/or warding off predators.
Adult amphibians can range in size from approximately 10 mm (3/8-inch) in length to approximately 180 cm (70-inches) in length. The largest amphibian is reported to be the Chinese Giant Salamander, which can reach lengths of 70-inches and can weigh more than 25-pounds. This salamander, which lives in China, is considered to be an endangered species.