Abstract
The objective of this study was to investigate the effects of salmon gonadotropin releasing hormone analog (S-GnRH-A) and human chorionic gonadotropin (HCG) on the serum levels of gonadotropins (GtHs) and sex steroid hormones in Manchurian trout during sexual maturity. Females in the treatment group were injected with 20 µg/kg S-GnRH-A and 400 IU/kg HCG, whilst males were injected with half the amount. Blood samples were collected at 0, 5, 10, and 20 days post injection (dpi). The results showed an increase in female follicle-stimulating hormone (FSH) levels in the treatment group at 5 dpi, and from 5 dpi onwards, a difference was observed between the groups, with higher FSH levels in the treatment group compared to the control group. In males, FSH levels showed group differences at only 5 dpi (p