ABSTRACT. This study was conducted to determine the effect of different concentrations of oestrogen hormone, 17β-estradiol (E2) on feminization for the production of all female P. monodon postlarvae, as well as survival rate and growth rate. The treatments consisted of three replicates of each diet containing six concentrations of oestrogen hormone, E2 at 0, 200, 400, 600, 800 and 1,000mg/kg feed. The experiment was carried out continuously for 50 days. At termination of experiment, the specimens in each treatment group were individually weighed and measured for their wet body weight (BW) and total length (TL) to estimate the mean final BW and TL, and the specific growth rate (SGR). The mean sex ratio values of male to female with the concentration of 0, 200, 400, 600, 800 and 1000 mg/kg were 1:1, 1:1, 1:2, 1:2, 1:4 and 1:5 respectively. The mean survival rate for 0, 200, 400, 600, 800 and 1000mg/kg were 42.33% ± 2.52, 37.67% ± 2.52, 38.67% ± 2.08, 47.33% ± 2.52, 41.00% ± 3.00 and 40.67% ± 2.08 respectively. The mean final TL and BW were 24.57 mm ± 2.84 and 0.11 g ± 0.05 for control, 26.97 mm ± 2.99 and 0.16 g ± 0.07 for 200 mg/kg concentration, 28.95 mm ± 2.30 and 0.20 g ± 0.06 for 400 mg/kg concentration, 30.77 mm ± 4.33 and 0.24 g ± 0.09 for 600 mg/kg concentration, 32.97 mm ± 5.59 and 0.27 g ± 0.06 for 800 mg/kg concentration and, 34.54 mm ± 5.32 and 0.32 g ± 0.08 for 1000 mg/kg concentration. The mean SGR for control treatment of P. monodon PL after 50 days was 2.67 g/day ± 0.18 while for E2 hormone concentration treatments of 200, 400, 600, 800 and 1000 mg/kg were 3.31 g/day ± 0.003, 3.86 g/day ± 0.13, 4.15 g/day ± 0.50, 4.41 g/day ± 0.02 and 4.74 g/day ± 0.30 respectively. The study shows that as the concentration of E2 hormone increased, the female sex ratio and the growth rate of P. monodon PL also increased. The number of PL surviving in all hormone treated diets was similar to the control treatment. But, treatment of 600 mg/kg shows the highest survival rate compared to the other treatments. Treatment 600 mg/kg can be considered the most effective concentration for survival in the study.
KEYWORDS. 17β-estradiol, feminization, Penaeus monodon, postlarvae, growth performance, survival rate.
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