Relationships among Gonad Weight, Liver Weight and Body Weight of Major, Common and Some Chinese Carps under Composite Culture System with Special Reference to Pond Fertilization

The relationship of gonad weight and liver weight with body weight of six fish species viz; Catla catla, Labeo rohita, Cirrhina mrigala, Hypophthlamichthys molitrix, Ctenopharyngodon idella and Cyprinus carpio under the influence of artificial feed, broiler manure, buffalo manure, N:P:K (25:25:0) and a control pond were examined after a rearing period of one year. The positive relationship between gonad weight and body weight was significant which showed the dependence of gonadal development on body weight in all the six fish species. The currelation coefficients were higher in female fishes. However, the major carps had a much smaller proportional gonadal weight as compared with Chinese carps and a common carp due to their faster growth rate. The overall comparison of six fish species under different experimental treatments revealed that highest liver weight was observed for C. idella closely followed by C. carpio. The maximum correlation value was observed with H. molitrix under the broiler manure. The maximum Gonadosomatic Index (GSI) remained as 32.63 for C. carpio followed by C. idella. The maximum value for Hepatosomatic Index (HSI). remained 1.99 for C. idella followed by C. mrigala.