عنوان مقاله [English]
The survey was carried out at the Shahid Bahonar Kalardasht Salmonids Reproduction Center (KSRC) during spawning season at 2009. A number of nine mature males (three years old) and 11 female Caspian brown trout,grown in the Salmonids Reproduction Center, were used. In the first stage all of male brood stocks (9 male) striped sperm sampling separately. Fertilization was made with each group’s sperm mixture and striped eggs in part of the five female and then eggs hardness process, transferred to the three trays in a incubation trays then the incubation process trends were evaluated. 14 days after the first stage, the second stage of sperm stripping occurred and 27 days after the second stage, third stage of sperm stripping as well as making first phase sperm stripping was implemented for each stage group of the three females. At the end of each three stages of sperm stripping, sperm density, spermatocrit percentage, sperm volume, sperm motility and morphology of spermatozoa (percentage of abnormal spermatozoa) were recorded and investigated. Its effect on fertilization rate, eyed eggs, hatching rate and larvae survival during repetitive sperm extraction were measures. The results showed that there were significant differences between the volume, motility, sperm morphology and fertilization rate during third phase of the study (P<0.05). The highest fertilization rate observed in the first stage of sperm extraction (97.33±1.53%) and lowest fertilization rate observed in the third stage of sperm extraction (7.25±6.25%). In this study, sperm density, spermatocrit, the percentage of eyed eggs, hatching and larvae survival in all the third stage was not significantly different (P>0.05). However, due to LSD test, percent survival of larvae had differences in stage 2 and 3.