Figure 2 Histological sections of fry at age of 21–35 days posthatching treated with 17a-MT showing: (a) the ovary of female treated with 40 mg of 17a-MT/kg of feed, showing the ovary contained perinucleolus oocytes (arrow head) and ovarian cavity (arrow) (H&E) 400·. (b) Presumptive testes treated with 60 mg of 17a-MT/kg of feed, showing primordial germ cells (arrow) and future of efferent duct (H&E) 400·. (c) Presumptive testes treated with 80 mg of 17a-MT/kg of feed, showing primordial germ cells (arrow) and presumptive efferent duct appeared towards the outer margin of testes (arrow head) (H&E) 400·. (d) The ovary of female after 75 days posthatching treated with 60 mg of 17a-MT/kg of feed, showing many degenerated oocytes. (e) The ovary of female after 75 days posthatching treated with 80 mg of 17a-MT/kg of feed, showing many degenerated oocytes (H&E) 400·. (f) The ovary of control female after 1 year showing the oocyte appeared in ripe stage (arrow) and few numbers of young oocytes (arrow head) (H&E) 100·.