4. AMPHIBIANS

Those are the characteristics used to define the amphibian class:

1. They are mainly carnivorous, but they are some omnivorous species too. We can distinguish what they eat according to their shape and volume. Little amphibians are usually insectivorous (frogs). But, when they are tadpoles they might be omnivorous too.

2. They are oviparous, it means that they lay eggs, and those legs must not be incubated for a period of time.

3. Offspring are not feed by their parents; they can be independent when they are born.

4. They are cold blooded and breathe through gills when they are little and through lungs after suffering a metamorphosis.

5. They have a moist skin, and they can also breathe through it. Some amphibians are venomous (some salamanders and frogs for instance).

6. They usually spend some of their time in water (mainly after being born) and if they live on earth, always in humid places.

7. Scientist recognizes a total of 7,511 species of amphibians.