the effects of dietary supplementation of astaxanthin and

the present research was aimed to study the effects of different sources of carotenoids and their varying concentrations on the reproductive functions of goldfish. the study was carried out in seven treatments with three replicates at the bony fish hatchery complex (rasht, iran) from december 2011 to may 2012. experimental diets containing 50, 100, and 150 mg kg-1 astaxanthin and 50, 100, and 150 mg kg-1 ?-caroten along with a carotenoid free basic carp feed as control were utilized. the goldfish broodstock were fed with the formulated diets for a period of four months. in may, eggs obtained from the female goldfish were fertilized with the semen of identical male goldfish fed with control diet and the absolute, working and relative fecundities and egg fertilization along with egg survival rate were estimated for different treatments during incubation period. the results showed that there was no significant difference in the fecundity rates among different diet treatments. nevertheless, the diameter and the number of egg per gram of the fertilized eggs in fish in the a150 (astaxanthin 150 mg kg-1) treatment were greater than those in the other treatments (p ? 0.05) and this treatment showed higher egg survival rates in the incubation period (p ? 0.05). correlation of egg astaxanthin with fertilization rate and survival rate was significant. moreover, there was significant correlation between ?-caroten and survival rate (p ? 0.05).