4. Amphibians
General characteristics:
Adults are terrestrial vertebrates.
Carnivores
Always live in wet places.
Characteristics of amphibian bodies:
Begin life in water.
Four limbs or legs:
Poikilothermic:
Skin with no covering:
Mucus keep skin moist and viscous.
Many species have poison glands for protection against predators.
Glands in the skin produce mucus.
Aquatic ones usually have webbed feet (toes connected by interdigital membranes). The anterior ones with 4 fingers and on the posteriors legs 5 fingers.
Body temperature varies depending on the temperature of their environment.
Many amphibians hibernate underground, under rocks or inside tree trunks during winter.
Amphibians without tails 
Short body.
Hind legs (patas traseras) are more developed than the front legs.
Frogs and toads.
Amphibians with tails
Long, thinner body.
Four short legs of equal length.
Salamanders and newts.