Polyculture using two major cmp species of indigenous carp (Rohu, bhakur and naini)
and exotic CGI]J (silver catp, bighead carp and grass carp) stocked in two stocking ratios
(80:20) was carried out for 240 days ji·otn February 1988_ to October 1999 in two
different stocking densities (5000 jingerlingslha and 7000 jingerlings/ha). Av. wt. offish
40-60 g size was stocked in earthen ponds (40 m x 10m). The common carp growth wps
highest (4.5 glday and 4.1 glday) when stocked exotic catps as major species (,80%) in
both stocking densities (7000 .fingerlingslha and 5000 jingerlingslha, respectively)
followed by silver carp (~.4-3.6 glday) and bighead carp (2.5-3.5 glday) when stocked
exotic carps as major species (80%). The growth rates of grass carp, rohu ·and naini
were low (1.3-1. 7 glday) with slightly higher growth rate of bhakur (1.8-2.0 g/day) ·
showing no differences either in stocking ratios or stocking densities. The productivity
obtained highest 4.2 Mtlha when stocked 5000 jingerlingslha using exotic carp as major
species (80%) followed by 3.5 Mt/ha when stocked 7000 jinger/ingslha also using exotic
carp as major catp. The lowest productivity was 2. 0 Mt/ha when stocked 5000
.fif!gerlings/ha using indigenous carp as major species (80%). The survival rates did not
show much difference in all treatments and remained between 75-84%.

Polyculture using two major cmp species of indigenous carp (Rohu, bhakur and naini)
and exotic CGI]J (silver catp, bighead carp and grass carp) stocked in two stocking ratios
(80:20) was carried out for 240 days ji·otn February 1988_ to October 1999 in two
different stocking densities (5000 jingerlingslha and 7000 jingerlings/ha). Av. wt. offish
40-60 g size was stocked in earthen ponds (40 m x 10m). The common carp growth wps
highest (4.5 glday and 4.1 glday) when stocked exotic catps as major species (,80%) in
both stocking densities (7000 .fingerlingslha and 5000 jingerlingslha, respectively)
followed by silver carp (~.4-3.6 glday) and bighead carp (2.5-3.5 glday) when stocked
exotic carps as major species (80%). The growth rates of grass carp, rohu ·and naini
were low (1.3-1. 7 glday) with slightly higher growth rate of bhakur (1.8-2.0 g/day) ·
showing no differences either in stocking ratios or stocking densities. The productivity
obtained highest 4.2 Mtlha when stocked 5000 jingerlingslha using exotic carp as major
species (80%) followed by 3.5 Mt/ha when stocked 7000 jinger/ingslha also using exotic
carp as major catp. The lowest productivity was 2. 0 Mt/ha when stocked 5000
.fif!gerlings/ha using indigenous carp as major species (80%). The survival rates did not
show much difference in all treatments and remained between 75-84%.