Question

In a fresh water composits fish culture mention basis of selection of varieties of fishes name any varieties of fishes and write 1 advantage and 1 Dis advantage of composite fish culture

Answer 1

the basis of selection is the zone in which the fish feed. it is done so that the fish don't have to struggle and compete for food with other fish . for example :
Catla is surface feeder
rohu is middle feeder
common carpse is bottom feeder
grass carpse is weeds feeder

advantage is that the people involved in this occupation earn a lot of money by taking care of fish.

disadvantage is that most of the fish breed during monsoon so , there is lack of space as most fish come to surface for breeding. although , for this , hormonal stimulisation is used.
another disadvantage is lack of good quality seeds available....