Regarding the role of sex-reversed fish in production of all-female rainbow trout, sperm traits of neomale rainbow trout (treatment 1) were compared to those of normal (XY-male) males. Sperm sample were obtained directly by stripping from normal males (control) or by surgery of testis (treatment 2). Spermatocrit, sperm motility, duration of sperm motility in water and diluent solution, fertilization rate and the percentage of produced normal larvae, were compared. Final results revealed that all assessed traits were identical, expect spermatocrit and sperm motility. There was no difference between spermatocrits from neomales (84%) and those from normal males of treatment 2(78%), but the spermatocrit from these two groups were higher than spermatocrits from normal males (35.33%) in control. Also number of motile spermatozoa from normal males of control was higher than motile spermatozoa from neomales. Also, this trait of sperm from neomales was higher than that of normal males of treatment 2 (P<0.01). Gonadosomatic Index (GSI) assessment results showed that GSI was higher in neomales (P<0.05). The results also suggest that the use of diluent solution leads to longer period of sperm motility duration in neomales (P<0.05).
