Survivality of Mono-Sex Tilapia (Oreochromis niloticus) Fry Using 17-α Methyltestosterone in a Commercial Hatchery of Chittagong, Bangladesh

The research was undertaken to develop the sex reversal technique of tilapia by using 17-α methyltestosterone. Locally available materials were used to prepare some hatchery equipments. Fry were treated with four different hormone doses of 15, 30, 60 and 120 mg kg-1 of feed in hapa I-IV, respectively in the ponds. The stocking density of fry was maintained 3000 m-2 in the experimental hapas. Physico-chemical parameters varied from as temperature 26.5-29°C , pH 6-8, DO 4.5-7.5 mg L-1, water transparency 16-35 cm, alkalinity 48-78 mg L-1, hardness 50.7-155 mg L-1. The sex reversal efficiency was found 88.33, 90.83, 96 and 78.33% in hapa I-IV, respectively. The highest sex reversal efficiency was obtained in hapa III where fry were treated with 60 mg 17-α methyltestosterone kg-1 feed. The survival rate (%) were recorded 92.45, 95.41, 93.75 and 89% in hapa I-IV, respectively. The highest survival rate (95.41%) was found in hapa II.