Monosex fish production in aquaculture, methods, benefits, limitation and future aspects

In some cases, sexual maturation and reproduction show significant adverse effects on production trend so, monosex production has a key role in fish aquaculture. Respecting economic importance of sexual dimorphisms in growth rate, focusing on the sex with greater size and higher growth rate is necessary. Sexual separation, interspecific hybridization, thermal or electrical treatments, hormonal manipulation using synthetic steroids or using medicinal or humic compounds are within the main methods for monosex fish production. Among them, hormonal sex changes is one of the most efficient biotechnological methods, which cause some changes in normal hormonal sex differentiation in fish. Using synthetic sex steroids at higher than recommended dose or longer duration can cause significant adverse effects on fish such as sterility, negative feedback on immune and some endocrine gland and liver functions. In this manuscript, the benefits and production methods of monosex fish followed by sex determination mechanisms and systems in fish are summarized. Then some new environmental friendly methods such as using safer sex steroids, electrical shocks and/or medicinal plant compounds for fish sex changes are fully described. Finally the limitation of current knowledge regarding production of monosex fish are mentioned.