عنوان مقاله [English]
Rainbow trout is the only species of rearing cold water fish in Iran. One of the main problems in its culture is artificial propagation and production of larva. Among of those, male broods have significant role in propagation process. For this target in the propagation season in 2008 the effect of reproductive performance of different age of male broods on fertilization, eyeing, hatching and survival rates until absorption of yolk sack stage in rainbow trout, were studied. For these studies, 3 groups of male broods (3, 4 and 5 years old) were fertilized with female fish individually. The results showed that in the studied treatments there was significant difference in the mean of fertilization rate, number of fertilized eggs, survival rate to eyeing stage and hatching rate (P£0.05). further, there was significant difference in milt volume between 3, 4 and 5 years old male broods (P£0.05). The results confirmed that three-year-old males have maximum of espermatocrite rate and differ from four and five-year-old males (P<0.05). The present study showed that the produced eggs from fertilization of four-year-old males milt and mixed females ova have maximum rate in fertilization rate (97%), survival rate until eyeing (97.21%), hatching rate (90.50%) and survival rate until absorption of yolk sack stage (88%).