Production of monosex male populations of European seabass, Dicentrarchus labrax L-by use of the synthetic androgen 17α-methyldellydrotestosterone

An investigation was undertaken to study the effect of the synthetic androgen 17 alpha-methyldehydrotestosterone on the sex reversal and gonadal development of the European sea bass Dicentrarchus labrax L. A combination of three different hormonal doses (0.5, 3, 5 mg/kg food) and three treatment durations (30, 60, 90 days) was tested starting at 84 days post-hatching. Complete and permanent masculinisation occurred in 100% of individuals at all times. The range of treatments did not significantly compromise the gonadal development. However, testicular deformities were observed in low proportions (less than 10%) of both treated and control groups. (C) 1999 Elsevier Science B.V. All rights reserved.