Effect of male broodfish age on efficiency of artificial fertilization in bighead carp (Aristichthys nobilis)

Bighead carp (Aristichthys nobilis) is one of the economically valuable fishes in polycultural systems. One of the main problems in it’s culture is artificial propagation and production of larva. Meanwhile, male broods have significant role in propagation process. For this reason in the propagation season at 2009, was studied the effect of male broods age on artificial propagation efficiency in bighead carp. 3 females (4 years old) were fertilized with 3 male age groups include: 3 years old (treatment 1), 4 years old (treatment 2) and 3+4 years old (treatment 3) individually. The sperm mobility duration, percentage of motile spermatozoa, sperm pH and density and hatching rate did not show significant differentes (P>0.05) between 3 age groups, but spermatocrit was significantly higher in 4 years old males (P<0.05). The maximum fertilization rate, and survival rate were observed in. treatment 3 (P<0.05). This study showed that, the composition of 3 and 4 years old males sperm had a positive effect on fertilization performance.