Control of Sexual Differentiation: Applications in Aquaculture

Authors: Weber, Gregory - Greg

Submitted to: Encyclopedia of Fish Physiology, From Genome to Environment
Publication Type: Book / Chapter
Publication Acceptance Date: 8/21/2023
Publication Date: 9/25/2023
Citation: Weber, G.M. 2023. Control of Sexual Differentiation: Applications in Aquaculture. Encyclopedia of Fish Physiology, From Genome to Environment. B9780323908016000690. https://doi.org/10.1016/B978-0-323-90801-6.00069-0.
DOI: https://doi.org/10.1016/B978-0-323-90801-6.00069-0

Interpretive Summary: The control of sex determination is applied widely in aquaculture to take advantage of sexual dimorphic production traits, improve production efficiency, and for genetic containment. Sex differentiation in fish is labile allowing for the manipulation of the sex of individuals primarily by treatment with exogenous endocrine factors or exposure to environments conducive to the expression of a specific sex. Artificial gynogenesis and androgenesis can also be used to obtain monosex progeny. In some cases, interspecies hybridization can yield skewed sex ratios.

Technical Abstract: There are over 30,000 species of fish of which over 500 are included in the Food and Agriculture Organization’s aquaculture listing. However, few farmed species are considered domesticated with even the most genetically improved lines still resembling their wild conspecifics in most details. Furthermore, the life cycle of many cultured species is not yet considered highly controlled in captivity which limits what technologies can be applied to improve production. One area of fish physiology that is unique compared to other farmed animals is the extent of their gonadal plasticity which allows fish farmers opportunities to control the sex of their production animals that is unparalleled in other forms of animal agriculture. Controlling sex differentiation in fish is relatively easy to accomplish, and thus, it has been and will continue to be one of the first and most effective ways fish farmers can improve the production traits of their cultivars to increase profit, regardless of the commercial maturity of that industry or farm. Incentives and opportunities for sex control in aquaculture are abundant. Most fall into the categories of taking advantage of sexually dimorphic production traits, increasing efficiency of production, and genetic containment. Approaches to controlling sex differentiation in aquaculture include interspecies hybridization, artificial gynogenesis and androgenesis, exposure to biotic and abiotic environmental factors that influence sex, and treatment with exogenous endocrine compounds.