Sex reversal of tilapia using methyltestosterone to produce all-male monocultures is widespread but raises welfare and food safety concerns. Alternatives are available but not widely adopted.
Tilapia sex reversal via hormonal treatment raises welfare questions about exposing developing larvae to synthetic androgens during a critical developmental period. While the direct welfare impact on larvae is not fully characterised, concerns include disruption to normal developmental processes and potential for malformations. The environmental impact of methyltestosterone runoff from treated ponds affects aquatic ecosystems and non-target species. Alternative approaches including YY genetics avoid hormonal treatment entirely. Consumer and regulatory pressure is beginning to encourage alternative approaches, though the economic advantages of hormonal sex reversal make transition challenging without market incentives.