The effets of combined phytoestrogen administration on growth performance, sex differentiation and body composition of sharptooth catfish Clarias gariepinus (Burchell, 1822)

The present study was conducted to investigate the effects of Genesis (G, a commercial mixture of phytoestrogens) on growth, body composition and sex differentiation of Sharptooth catfish Clarias gariepinus. Genesis is a commercially available product on USA and European markets used for menopausal complaints as an alternative medicine. Different concentrations (0 mg G 30 L-1, 210 mg G 30 L-1, 420 mg G 30 L-1, 630 mg G 30 L-1, 750 mg G 30 L-1 and 1500 mg G 30 L-1) of Genesis were administered by immersion of newly hatched larvae (averaging 2.27±0.12 mg) every 3 days for 30 days then immersion treatments were ceased and all groups reared in the same condition for the later 90 days, a total 120 days experimental period. At the end of the trial, specific growth rate of the females increased with the increasing concentration of Genesis up to 420 mg 30 L-1 (P<0.05), but different concentrations of Genesis did not affect the growth performance of males (P>0.05). The highest value of protein content (21.60%) was observed from the 420 mg G 30 L-1 group and found significantly different from the control and other groups (P<0.05). Also, lipid contents were significantly affected by the Genesis concentrations and the highest lipid contents were detected in the 210 mg G 30 L-1 (5.98%) and the 630 mg G 30 L-1 (6.66%) groups. Although among the dosages used in the present study, 1500 mg G 30 L-1 was the most effective dosage that ensured maximum female ratio (69.77%), the sex ratios observed for 0, 210, and 420 mg G 30 L-1 treatment groups were nearly the expected ratio of 1:1 (male: female). Therefore, it was concluded that usage of higher doses and treatment durations of Genesis could be more effective for all-female production of the Sharptooth catfish population