Amphibians
Amphibians are ectothermic, four-limbed vertebrate animals. All extant (living) amphibians belong to the subclass Lissamphibia, with three living orders: Anura (frogs), Urodela (salamanders), and Gymnophiona (caecilians). They are mostly semiaquatic and have adapted to inhabit a wide variety of habitats, with most species living in freshwater, wetland or terrestrial ecosystems.
Mollusca
They are sluggish invertebrates, with a thin fleshy envelope or mantle covering the visceral organs.The term Mollusca was derived from the term given by Aristotle to cuttlefish. Mollusc means soft. These organisms are found in the terrestrial as well as in deep seas.
Reptiles
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic ('cold-blooded') metabolism and amniotic development. Living reptiles comprise four orders: Testudines (turtles), Crocodilia (crocodilians), Squamata (lizards and snakes), and Rhynchocephalia (the tuatara)
