Document Type : Short communication
Department of Environmental Science and Fisheries, Faculty of Natural Resources, Karaj, 31585-4314, University of Tehran, Iran
Department of Fisheries, Tonekabon branch, Islamic Azad University, Tonekabon, Iran
Shahid Rajaee Fish Stocking Center, 833, Sari, Iran
The objective of this study was to measure the concentrations of steroid hormones (testosterone, 17β-estradiol and progesterone) in kutum Rutilus frisii kutum during spawning period. Serum testosterone level in gravid fish (14.52 ± 0.03 ng/ml) was higher than that (0.54 ± 0.11 ng/ml) in ripe fish (P < 0.05). Levels of 17β-estradiol and progesterone were lower than 1 ng/ml with no significant difference between ripe and gravid fish (P > 0.05). The hormonal profile indicates that gravid fish are ready to ovulate.