Masculinization of the gynogenetic juvenile ship sturgeon (Acipenser nudiventrisLovetsky, 1828) using 17α‐methyl testosterone

Abstract

In sturgeons, the induction of gynogenesis and sex reversal could be important for potential production of neomale sturgeon and all-female progeny for caviar production. The aim of this study was sex reversal of ship sturgeon (Acipenser nudiventris Lovetsky, 1828) gynogen into male sex. Five-month-old gynogens were sex reversed into male by including 17α-methyl testosterone in their food for 7 months. Three treatments were considered as follows: (a) without treated (gynogen control), (b) 10 mg MT/kg diet, and (c) 50 mg MT/kg diet. All treatments (60 individuals) were sampled both the 30 and 36 months old and their sex was determined using classical histology method of gonad. The sex ratio of the progenies in the gynogen control were 73.3% female and 26.7% male. In treatment of 10 mg MT/kg feed, 18 specimens were studied that half of them (50%) showed pseudo-testicular structure in the female gonad. That is 50% of the specimens were intersex, 27.7% were male and 22.3% were female. All of the fish fed by 50 mg MT/kg feed had been sex reversed to male. Sexual maturation of these fish had been recognized in stage III at 36 months old. In conclusion, 50 mg MT/kg feed found as effective dose for successful sex reversal in gynogenetic ship sturgeon.