ZOOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site amphibian Anatomy of a frog and some other examples of amphibians A vertebrate organism of the class Amphibia, such as a frog, toad, salamander, or some types of newts, having an aquatic early stage (e.g. tadpole) and developing air-breathing lungs as an adult (e.g. frog). There are three living orders: Urodela (newts and salamanders), Anura (frogs and toads), and Apoda or caecilians. In contrast to fish, amphibians have a smooth, scale-less skin (except for some limbless forms). It is used for respiration. The paired limbs are jointed structures, and though the basic number of fingers is five, many amphibians have less than this. Living of land their body has to be supported (the weight of water-dwelling creatures is supported by the water) and the backbone acts as a girder transmitting the weight to the four legs. When moving quickly, newts wriggle in a way that resembles that of fish, but slow movement is brought about by the movement of the legs, the body being raised up off the ground. In frogs the skeleton and musculature are specialized for jumping and swimming – the number of vertebrae is much reduced. Adult frogs have paired lungs. Only the tadpoles have gills, though some adult salamanders retain their gills. Related category    • ZOOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP