Question

29.a) Why do fishes die when taken out of water?​

Answer 1

Though some fish can breathe on land taking oxygen from air, most of the fish, when taken out of water, suffocate and die. This is because gill arches of fish collapse, when taken out of water, leaving the blood vessels no longer exposed to oxygen in air.

Answer 2

fishes can breath only the dissolved oxygen from water. if fishes are taken out they won't be able to inhale atmospheric oxygen. so they die.