This paper presents the results of two experiments for the masculinization of tilapia fry (Oreochromis niloticus) through the use of an aromatase inhibitor, letrozole, administered in fish feed. The first experiment evaluated the effect on growth, survival, and the percentage of masculinization of sexually undifferentiated fish undergoing letrozole doses of 50 (T1), 100 (T2), and 200 (T3) mg kg-1 during four weeks. There was a negative control group (C0) feed without letrozole and a positive control group (C) that received 60 mg kg-1 of 17 alpha-methyltestosterone (MT) in feed. No significant differences in growth (weight and length) and survival were found between treatments and control groups. Treatments T1, T2, T3 showed a percentage of 90%, 100% and 93% of males, not showing significant differences. It was found 66% of males in group C and 45% in group C0, showing significant differe...

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Acuicultura