Masculinization under combined administration of an androgen and an aromatase inhibitor in the Ussuri catfish, Pelteobagrus ussuriensis (Dybowski, 1872)

Abstract

In this study, we used the central composite experimental design and response surface methodology to investigate the masculinization as well as larval growth, survival under combined administration of an androgen (17α-methyltestosterone, MT) and an aromatase inhibitor (letrozole, AI) in the Ussuri catfish, Pelteobagrus ussuriensis. The results showed that the masculinization was significantly promoted by MT and AI. The nonsignificant MT × AI interaction indicated that MT acted on masculinization independently of AI and vice versa, suggesting that they may function through different molecular pathways. The impact of MT was greater than that of AI, indicating that masculinization via the direct action of MT was more important than that of AI during masculinization. The optimal MT/AI dosage was obtained by simultaneously optimizing three reliable models in consideration of the growth and survival. A verification trial under the commercial setting showed that this optimal MT/AI combination had greater potential for application to culture production, albeit not complete sex reversal. Our results suggest that using a combined administration of MT and AI to masculinize the Ussuri catfish be preferred.