The culture performance of 17-α-methyltestosterone treated tilapia (Oreochromis niloticus) in fertilized ponds

Tilapia is the leading farmed species in all over the world due to its taste and the consumer preference. one of the main constraints in tilapia culture is its early maturation. the objectives of this study were to determine the effect of different doses of 17-a-methyltestosterone on the growth of oreochromis niloticus. for this study,the experiment expanded over a period of 166 days in four earthen ponds. fertilization of all the ponds was done with cowdung at the rate of o.lg n/100 g wet fish body weight daily. the supplementary feed (rice polish) was given at the rate of 2% fish body weight daily. one pond was designated as control pond in which tilapia was added which was not sex reversed by 17-α-methyltestosterone. in the treated ponds,17-α-methyltestosterone was applied at the rate of 50,70,and 90 mg/kg feed. the net fish production was calculated as 850.48,1026.94,1117.92 and 1277.17 kg/ha/year with 0,50,70,and 90 mg 17-a-methyltestosterone/kg feed pond,respectively. the overall results indicated that the sex-reversed oreochromis niloticus showed markedly increased growth than in control ponds. however,maximum fish growth and production were observed with 90 mg/kg 17-α-methyltestosterone while minimum decrease in fish production was recorded with 50 mg/kg 17-α-methyltestosterone. the tilapia which was produced through sex reversal had a capability to grow more as compared to normal tilapia. © pakistan academy of sciences.