The effect of 17 alpha-methyl testosterone, aromasin and green light radiation on the production of all male populations in (Xiphophorus helleri)

The alpha-17-methyltestosterone is one of the androgens hormone involved in the sexual cycle and is used to increase growth and change sexual secondary charactristics. The aim of this study was to induction of masculinization in Xiphophorus helleri. in this experiment, fish in experimental groups including: Control group, 17 alpha-methyl testosterone with 3 levels (400, 300 and 500 mg/kg diet), aromasin with levels (45, 30 and 60 mg/kg diet) and green light radiation (12 hours of light and 12 hours of darkness) each with 3 repetitions for 45 days. Results showed that in group with 45 mg aromasin /kg diet (79.9%) higher percentage of masculinization were observed. The percentage of masculinization in females treated in treatment green light was significantly higher than other treatmens. Also, The percentage of survival in the green light group and aromasin was higher than 17 alpha-methyl testosterone group. In general, according to the results of masculinization, the percentage of masculinization in females treated with 45 mg aromasin/kg diet and green light treatment were recognized as the highest results, respectively. Overall, the results showed that in order to induction of masculinization in swordfish, Aromasin could be a suitable alternative to methyltestosterone.