Four different doses such as 50, 100, 200 and 400 mg estradiol-17β/kg feed
were administered for 40 days on African catfish bearing an average length 5.1
mm and weight 4.7 mg. Growth, survival and sex-ratios were evaluated. The mean
length of fry after hormone feeding phase were found to be more or less similar
in all the treatments. The mean weight of fry of the group fed on diet containing
100 mg estradiol-17β/kg feed was found to be significantly higher than
those receiving 50, 200, 400 mg estradiol-17β/kg feed and control. The
groups of fry treated with 400 mg estradiol-17β/kg feed and control group
showed lower survival compared to those with other doses of hormone. No negative
effect on growth and survival of estradiol-17β was however, observed in
this study. The doses of 100 mg and 50 mg estradiol-17β/kg feed resulted
in 87.76% and 80.85% female fish respectively which were significantly (p<0.01)
higher than that of the expected frequency of female fish in a normal population.
The dose of 400 mg estradiol-17β/kg feed resulted in relatively lower frequency
of female fish.
Z. Hossain , M.M. Rahman and S. Afruj , 2002. Effects of Different Levels of Estradiol-17β on Growth, Survival and Sex-ratio
of African Catfish (Clarias gariepinus, Burchell). Pakistan Journal of Biological Sciences, 5: 355-358.