Polyculture
The most successful system of pond fish culture is the polyculture of three Indian major carp species - catla, rohu and mrigal along with three Chinese carps viz. silver carp, grass carp and common carp.
Modification
On the basis of growth performance of different species, modifications are often made in stocking density, species ratio, fertilization schedule and supplementary feeding programme in different agroclimatic conditions.
Three-Tier Culture
The carp culture system as a whole is operated as a three-tier culture system where the practices are adopted for rearing fish during their different stages till they are harvested.
Fry Stage and Harvested
Relatively smaller, seasonal ponds are mainly used for rearing spawn to fry stage and harvested after 2–3 weeks. Several crops (3–4) of fry are usually taken during the season. Pond fertilization by cattle manure and feeding with 1:1 mixture of oil cakes and rice bran is the usual practice.