Muhammad Mizanur Rahman *,Mostafa Shamsuzzaman MD ,Saad Mahmood ,Subrata Sarker ,Faruk Alam MD
With a view to assess the suitability of mono-sex Tilapia (Oreochromis niloticus) culture using downstream flow from hills by observing their growth, survival and production in watershed pond, an experiment was carried out in a commercial aquaculture farm Mrittika Fisheries, Odolia, Hathazary, Chittagong. The duration of {each} culture period was 4 months. Stocking densities of the three culture ponds were same as, 10 individuals/m2. All the fish were of same age group having mean body weight about 1.2 gm. A commercial pellet feeds were used at the rate of 20% of body weight during first 15 days and then the feeding rate was reduced to 18%, 15%, 12%, 10%, 8%, 6%, and 5%, receptively with 15 days interval and the measured survival rate of fish was 84.33%, 77%, 72.33%, 69%, 66.33%, 65%, 63.67%, and 62.67% receptively in 15 days interval. From the economic analysis it was found that the net profit accrued out of the three ponds (1.20 hector) was (BDR=Bangladeshi Taka, 1 US$=81 BDT) BDT 547177.77, whilst the operational cost was BDT 700544.23, the rate of profit ratio obtained is 78.11% in comparison to the operational cost. The results of the specific study indicate that the culture of tilapia in the watershed ponds by using downstream water flow is exceedingly suitable even with the high stocking density. The resultant production was good with high profitability with less input of operational cost and reduced risk.