The impact of captivity on fertilization, cortisol and glucose levels in plasma in kutum broodstock

  Gravid wild kutum broodstock, Rutilus frisii kutum, on their upstream migration to Valiabad River (northern Iran) were kept in captivity to allow them to ovulate (captive ripe). Then the impact of captivity on some reproductive and physiological parameters (i.e., plasma cortisol and glucose levels, fertilization percentage, gonadosomatic index and fecundity) were assessed and results were compared with those obtained from naturally ovulated broodstock (ripe). Plasma cortisol level was not significantly different between gravid and captive ripe broodstock but was significantly higher (P < 0.05) than that in ripe group. Glucose level was significantly higher (P < 0.05) in captive ripe compared to that in ripe or gravid groups. Mean gonadosomatic index, fecundity, and fertilization rate did not affect as a result of stress by captivity. Inverse relationship between plasma cortisol levels and fertilization rate was observed.