Question

What is amphibian ?

Answer 1

Amphibians are the animals that belongs to phylum-chordata (backbone)

Amphibia is a class within the chordata phylum.

They can survive in both aquatic and terrestrial habitat.

Major Characteristics;-

1) Cold blooded vertebrates (Ectothermic)

2) Body divide into head and trunk. Tail may be present.

3) Skin is smooth or rough having glands to keep moist.

4) They are usually without scales, if present, hidden beneath skin.

5) Gills (respiration organ) are present in larva stage, some adults have external gills e.g (Proteus)

6) Skull is dicondylic.

7) Heart is $3$ chambered ($2$ auricles, $1$ ventricle)

8) Kidney are mesotrophic.

9) Ear consists of internal and middle ear.

10) Fertilization is external.

11) Metamorphic is present, development is indirect.