Book excerpt: Cage is an enclosed space of rear organism in water that maintain free exchange of water with the surrounding water body, cage culture is an aquaculture production system where fish are held in floating net pens. Cage culture of fish utilizes existing water resources but encloses the fish in a cage or basket which allows water to pass freely between the fish and the pond permitting water exchange and waste removal into the surrounding water. India is having big potential of Cage Culture, because lake is having deep and sufficient water availability.