Fish and fish ponds
Three fish ponds located in a farm at Balliparru near Machilipatnam (latitude 16º 09’ N, longitude 81° 12' E) in Krishna district, Andhra Pradesh, India were chosen for the present study. The earthen ponds are designated as Pond A, B and C. In the three ponds Pangasius sutchi, Catla catla and Labeo rohita were stocked in the ratio of 4:1:1.5 at the rate of 20,785 fingerling/ ha. The fish were fed with supplementary feed mostly with deoiled rice bran, groundnut oil cake and slaughter waste at the rate of 2% body weight of fish per day. Prior to and after the release of fish, all the ponds were treated with organic manures such as poultry manure, compost and cattle dung, and inorganic fertilizers such as superphosphate. The