Effect of Varying Species Ratios of Silver Carp on the Growth Performance of Mrigal and Grass Carp in Semi Intensive Pond Culture System

Abstract

The present project was conducted to determine whether difference in stocking ratio of silver carps can affect the growth performance of mrigal and grass carp. Fingerlings of Ctenopharyndon idella, Hypophthalmicthys molitrix and Cirrhinus mrigala were stocked at the ratio of 15:45:45 and 15:45:30 in fertilized experimental pond 1 and 2 with two replicates. Results showed that stocking ratio, species combination and fortnights had significant effect on growth of fish (P<0.01). In pond 1, grass carp gained significantly higher body weight, followed by mrigal and silver carp (322g, 282g and 260g), while in pond 2 silver carp gained higher body weight followed by mrigal and grass carp (400g, 299g and 248g). Results showed that, pond 1 stocked with higher ratio of silver carp gave higher production of grass carp while, pond 2 stocked with lower ratio of silver carp produce higher production of mrigal. Overall net fish production of pond 1 (4036.52 kg) and pond 2 (4207.88kg) statistically varied non significant. From the production point of view it was concluded that high stocking of silver carp to grass carp ponds is a better proposition than to add it to mrigal ponds. Most of the ecological parameters showed highly significant seasonal differences but remained favorable during whole period of study.