List the adaptations of aquatic animals.

Explanation

The adaptations of aquatic animals include the following :
(i) In fish the pectoral fins and dorsal fins act as balancers and the cudal fin helps in changing direction as a rudder.
(ii) Stream lined body structure helps in the swift movement of animals in water.
(iii) Presence of air bladder filled with air helps for buoyancy.
(iv) Integument rich in mucous glands are protected by scales.
(v) With well developed excretory organs, they maintain water and ionic balance in their body.