Sex Control in Fish: Approaches, Challenges and Opportunities for Aquaculture

TLDR

Aquaculture is the fastest growing animal food sector and a key sustainable food security solution, yet controlling fish sex—critical for reproduction, growth, and product quality—remains a major research focus. This review introduces fish sex determination and differentiation mechanisms and surveys major sex‑control approaches for commercial species. We examine hormone treatments, ploidy manipulation, environmental cues, genetic markers, selective breeding, and transgenic methods, highlighting the challenges of implementing these strategies in commercial aquaculture.

Abstract

At present, aquaculture is the fastest growing sector of animal food production and holds great potential as a sustainable solution for world food security. The ability to control sex is one of the most important factors for the commercialisation and efficient propagation of fish species, due to influences on reproduction, growth and product quality. Accordingly, there is a large body of research that targets sexual development in commercially important species in an attempt to understand and control fish sex and reproductive function. In this review, we provide an introduction to sex determination and differentiation in fish, including the genetic, epigenetic and environmental factors that can influence fish sex ratios. We also summarise the major approaches used to control sex in fish and discuss their application in commercially important species. Specifically, we discuss the use of exogenous steroid hormones, chromosome ploidy, environmental manipulations, sex-linked genetic markers, selection for altered sex ratios, and transgenics and comment on the challenges associated with controlling sex in a commercial environment.