Serum levels of testosterone, 11-ketotestosterone and oestradiol-17β in three species of sturgeon during gonadal development and final maturation induced by hormonal treatment

Changes in serum concentrations of two androgens, testosterone (T) and 11-ketotestosterone (11KT), and oestradiol-17beta (E2) in male and female giant sturgeon Huso huso, Russian sturgeon Acipenser gueldenstaedtii and stellate sturgeon Acipenser stellatus were studied at different stages of gonadal maturity and after final maturation induced by hormonal treatment. Both male and female fish displayed a distinct increase in serum steroid concentrations during gonadal development. 11KT levels were significantly higher in males than females, with a positive correlation detected between 11KT and T concentrations. In maturing males and females, higher values of both 11KT and T were observed in stellate sturgeon compared to giant and Russian sturgeons. Vitellogenesis and high E2 levels were correlated in maturing sturgeon females. (C) 2004 The Fisheries Society of the British Isles.