Investigation of production possibility of monosex female and sterile fish in rainbow trout Oncorhynchus mykiss

This investigation carried out for the first time in Iran inorder to prodcution of monosex female and also sterilization in Rainbow trout. In this study, the eggs of general females were fertilized with the sperm of sex reversed male and so monosex female population was produced in second generation and sterilization carried out with oral administration of 17α methy 1 testosterone and immenrsion and oral administiration methods were used in embryonic stage and from commencing of acitve feeding of larvae, respectiverly. For sex reversal , 13 treatments were considered totally, that the most percentage of male (100%) was observedc in a treatment including of orally administration of 0.5 ppm hormone for 60 days after commencing active feeding (P<0.001). In the other treamtnet, different percentages of sex ratio including male, female, intersex and sterility were observed. The offspring of genral eggs fertilization with the sperm of masculinized fish were 100% female, chisquare test was shown the treatment of orally administration of 30 ppm hormone for 120 days after commencing active feeding that had been considered for sterilization, was produced 90% sterile fish (P