No abstract

The production of common carp (Cyprinus carpio) was studied in pond fertilized with cow-dung @ 0.1g N/10g in the presence of planktonic biomass. The correlation of planktonic biomass with water quality physicochemical parameters of three fish ponds, was studied. The parameters such as pH, temperature, dissolved oxygen, total alkalinity, total dissolved solids, total hardness, magnesium, calcium, light penetration, total solids, carbonates and bicarbonates, were analyzed in a laboratory using standard protocols. Data collected at the end of the present experimental study was subjected to an appropriate statistical analysis to appraise the correlation coefficients of planktonic biomass with several physicochemical parameters of three ponds under study. In most cases significant correlations were recorded between biomass and key physico-chemical attributes of the ponds.

Fish polyculture has resulted in high fish production per unit area, mainly due to the best utilization of all kinds of nutrients. In this nine month’s experimental study, five different fish species were stocked in five earthen ponds designated as control (one pond), treatment-T1 (two ponds) and treatment-T2 (two ponds). Fish stocked in T1 and T2 ponds were fed with a commercial feed containing 20% and 25% crude protein, respectively, whereas fish stocked in the control pond was fed with a conventional mixture of feed ingredients (fish meal, gluten, sunflower, and rice polish) having 20% CP. The fish was fed @ 3% of the fish wet body weight twice a day. The fish was sampled every fortnight. Physicochemical parameters of the ponds were measured daily. The results showed that the maximum weight gain (255 g) was recorded in Pangasius pangasius in treatment T2 and minimum (52.5 g) in Cirrhinus mrigala in the control pond. Overall, maximum fish production was recorded after harvest in treatment T2 followed by that in treatment T1 and control ponds, respectively. Overall, the commercial fish feed enriched with crude protein was very effective in promoting growth and development of pond fish.