A Whale:
1.Whale is a mammal. The hairs on its body are lost due to aquatic adaptation.
2.Respires with the help of lungs only.
3.It is viviparous i.e., give birth to young ones.
4.Females have mammary glands.
5.The forelimbs do not have claws and are flattened and modified into paddle-like flippers. The hindlimbs are absent in whales.
A Fish:
1.Scales are present over the body of fish. It belongs to Pisces.
2.Respires by means of gills.
3.It is oviparous i.e., lays eggs.
4.Mammary glands are absent in them.
5.Limbs absent. For locomotion, the fins are present.