Monosex male tilapia production uses hormonal sex reversal of fry to produce all-male populations. The welfare and ethical implications of this practice warrant consideration.
The use of androgens to reverse the sex of female tilapia fry raises ethical questions about the appropriate manipulation of animal physiology for production purposes. The immediate welfare impact of hormone treatment is uncertain but the immature immune and endocrine systems of newly hatched fry may be more vulnerable to exogenous hormone exposure than in adult fish. At the population level, monosex culture reduces the chronic aggression welfare cost of mixed-sex production, representing a welfare trade-off. The development of genetic alternatives to hormonal sex reversal would eliminate this welfare concern while retaining the production benefits of monosex culture.