COMPARISON OF PRODUCTION PERFORMANCE AND ECONOMICS BETWEEN MONO-SEX AND MIXED-SEX TILAPIA Oreochromis niloticus  

Mrityunjoy Kunda*, Aruna R. Deb and Md. J. Islam
 
Department of Aquatic Resource Management
Faculty of Fisheries, Sylhet Agricultural University
Sylhet-3100, Bangladesh
kunda.sau@gmail.com

Tilapia is one of the top ranked cultured species in the world. In Bangladesh tilapia culture is also increasing rapidly. Still a large number of consumers did not like hormone treated mono-sex tilapia, because there is a perception in the general people that there may have some negative effect on human health. Moreover, there is a good market demand of smaller size about 100-200g tilapia in the rural market due to lower price and which can be grown by 2-3 months. Considering these factors the study was conducted to assess the comparison of production performance and profitability between mono-sex and mixed-sex tilapia, Oreochromis niloticus. The experiment was carried out with two treatments each having six replications for a period of 99 days from 7 May to 12 August 2014, in 12 cages which were set up in a pond at Sylhet Agricultural University, Sylhet, Bangladesh. In the first treatment (T1), mixed-sex tilapia was stocked with a mean initial weight of 1.743±0.436g. In the second treatment (T2), mono-sex male tilapia was stocked with a mean initial weight of 1.756±0.482g. Fish were fed at the rate of 30% body weight of fish initially and gradually decreased up to 4% of body weight of fish at the last month of study. Feed was adjusted every 7 days interval depending on the body weight of tilapia. Water parameters, viz. water temperature, transparency, DO, pH, CO2, NH3, TDS, hardness, nitrite nitrogen were measured fortnightly.

During the study period water quality parameters found within the suitable range of fish farming. At 99 days of culture period, mono-sex male tilapia attained a significantly (P<0.05) higher mean final weight, 167.15 ± 13.297g in comparison to mixed-sex tilapia. However, there was no significant (P>0.05) difference of food conversion ratio and survival (%) between the treatments at the end of the study. The benefit-cost ratio was calculated as 1.47:1 and 1.59:1 for mixed-sex and mono-sex male tilapia, respectively. But it was observed that there were no significant differences of individual weight and gross yield of tilapia, at 72 days among T1 and T2 (Table 1). The comparative study suggested that within two and half month culture period mixed-sex tilapia can be cultured successfully instead of mono-sex male tilapia which is very safe for human health as because of mixed sex tilapia is not hormone treated.