Influence of Age of Common Carp (Cyprinus carpio) Broodstock on Reproductive Traits and Fertilization

In this study, we examined the age-dependent changes of sperm quality parameters and female properties in common carp. As well as, age-dependent reproductive performance of brooders was tested using two age groups of male and female (i.e. 2 and 3 years old brooders). For this aim, the brooders were crossed randomly from age classes. There were significant differences in sperm density and percentage of motile spermatozoa between ages, but duration of sperm motility and spermatocrit did not differ from two age groups. Some seminal plasma composition such as pH, chloride, acid phosphatase (ACP) and alkaline phosphatase (ALP) showed significant differences between two age classes. Female properties revealed change in egg diameter between two age groups. No significant differences were observed in other female properties between two age groups. According to our results, the higher fertilization rate (%91) and survival rate (%90) was found when the 2 years old males were crossed with 3 years old female (P<0.05). Also, highest hatching rate (%96) and larvae length during hatching were found when the 3 years old males were crossed with 2 years old female (P<0.05), while larvae length at initiation of active feeding (after yolks soc absorption) was higher when the combination of 2 and 3 years old males were crossed with 2 years old females.