Amphibians include ectothermic tetrapods such as frogs toads and salamanders. The distinguishing characteristic that separates amphibians from reptiles is their breeding behaviour. Most amphibians need a physique of water to breed as their eggs are shell-less. Furthermore, they undergo metamorphosis where the younger ones transform from totally-aquatic larval type (with gills and fins) to terrestrial adult kind. Lampreys and Hagfishes (Agnatha) – There are about forty species of lamprey alive today.
The vertebrate has a definite head, with a differentiated mind and three pairs of sense organs (nasal, optic, and otic [hearing]). This class of fishes is characterized by their skeleton which consists primarily of bone rather than cartilage (similar to sharks). Class Osteichthyes can be the largest class of vertebrates at present.
These extinctions cut back the diversity of life on the planet and destroy our ability to know all features of biology. We hope to indicate you the … Read More