Comparison of production performance and economics between mono-sex and mixed-sex tilapia (Oreochromis niloticus)

Abstract

The study was conducted to assess the production performance and economics between mixed- sex and mono-sex tilapia, Oreochromis niloticus. The experiment was carried out with two treatments each with six replicates for a period of 99 days from 7 May to 12 August 2014, in 12 cages in a pond of Sylhet Agricultural University, Sylhet. In the first treatment (T1), mixed-sex tilapia was stocked with a mean initial weight of 1.74 ± 0.44 g. In the second treatment (T2), mono-sex male tilapia was stocked with a mean initial weight of 1.76 ± 0.48 g. Fish were fed at the rate of 30% body weight (bw) initially and gradually decreased up to 4% bw until the end of the study. Water parameters, viz. temperature, transparency, DO, pH, CO2, NH3, TDS, hardness and nitrite were found within the range of fish farming. After 86 days and 99 days of culture period, mono-sex male tilapia attained a significantly (P<0.05) higher mean final weight and specific growth rate than mixed-sex tilapia. However, there was no significant (P>0.05) difference of food conversion ratio, specific growth rate and survival values between the treatments at the final harvest of study. The benefit-cost ratio was calculated as 1.47 and 1.59 for mixed-sex and mono-sex tilapia, respectively. However, it was observed that there were no significant differences of individual weight, gross yield and net yield of tilapia at 72 days between two treatments. Thus the study suggest that mixed-sex tilapia can be cultured economically like mono-sex tilapia until 72 days of culture period.