Achieving monosex male tilapia: a critical review of hormonal, biodegradable and genome editing strategies.

Nile tilapia culture faces significant challenges due to early maturation and uncontrolled reproduction, leading to stunted growth and overpopulation. The primary solution is producing all-male populations or sterile fish. While the synthetic androgen 17α-methyltestosterone has been the industry standard for hormonal sex reversal for decades, environmental and consumer safety concerns, including potential carcinogenicity, have driven the search for sustainable alternatives. This critical review examines the full spectrum of approaches for producing monosex male tilapia, encompassing traditional methods (manual sexing, hybridization), hormonal treatments (synthetic steroids, aromatase inhibitors), biodegradable options (plant extracts like Tribulus terrestris and Basella alba, animal by-products such as cattle and carp testes), and novel genetic strategies (YY male technology, genome editing). We highlight innovative biodegradable programs and discuss how nanoparticle-mediated drug delivery can enhance therapeutic efficacy. Furthermore, we explore how genome editing technologies like CRISPR-Cas9 offer groundbreaking potential for understanding and controlling sex determination systems. Finally, we critically evaluate these methods based on effectiveness, cost, scalability, and sustainability to guide future research and the development of more environmentally responsible practices for the tilapia aquaculture industry.