Amphibians (class Amphibia), such as frogs, toads, salamanders, newts, and caecilians, are ectothermic (or cold-blooded) animals that metamorphose from a juvenile water-breathing form, to an adult air-breathing form. Though amphibians typically have four limbs, the Caecilians are notable for being limbless. Unlike other land vertebrates (amniotes), amphibians lay eggs in water. Amphibians are superficially similar to reptiles. Amphibians are ecological indicators, and in recent decades there ha… (More on Amphibian)