An intensive way of farming fishes is the composite fish culture system. In such a system, five or six different species of fishes are grown together in a single fishpond. Fishes with different food habitats are chosen, so that they do not compete for food among themselves. For example, catlafeed on the surface of water, rohu are middle zone feeders, mrigal and common carp are bottom feeders, and grass carp feed on weeds. This ensures complete utilization of food resources in the pond. Such a system increases the fish yield.
A major problem with this system is that many of these fishes breed only during monsoon. However, the use of hormonal stimulations has provided a solution for this problem.