• Project Description and Objectives:

Rainbow trout is one of the most important cultivated fish species in Iran, the female fish gets more attractions recently because of its late maturation and higher growth rate in comparison to the male fish. There are many different methods to produce all-female population in trout fish. One of the most important one is to use neomale, phenotypically male fish (XX male) to fertilize female ova. So the first step is producing neomale fish based on all-female or mixed-sex larvae. In this project, all-female larvae from Iranian and Iranian-Spanish crosses were fed with diet containing different levels of steroid hormones for 90 days at 10-12 ºC. The growth and survival performance as well as sex ratio of the fish were analyzed.