The effects of dietary astaxanthin on the physiological, growth and survival of gold fish larvae (Carassius auratus)

The present research which aimed at identifying the effects of astaxanthin pigment in upgrading efficiency in producing goldfish larvae through 4 treatments and 3 replications was conducted in the winter of 2014. For this reason, a sum of 12,4m3fiber glass fish ponds were prepared where in each, 50 female goldfish breeders were introduced with an average body weight of 47.21±2.19g. Then, 4 diets containing zero level, 50, 100, and 150mg/k of astaxanthin were formulated and given to the fish for a period of three months based on 5% of their biomass. In late march of 2015, the female fish in each pond were individually fertilized with male fish that were only fed with the control diet. All the biological characteristics of female breeders were examined. In addition, at larval rearing stage, the larvae produced in each treatment were kept at separate tanks and larval variations in terms of yolk sac absorption, condition factor and larval survivability were checked across different treatments. Meanwhile, qualities such as larval morphology, notochord length, body depth, yolk sac surface area, both prior and after absorption were determined and contrasted. The results obtained in this research showed that the diets containing 150mg/k astaxanthin brought about a superior impact on the reproductive qualities of female goldfish breeders, the eggs as well as the larvae. The hatched eggs, the larvae produced in the treatment and the survivability rate were higher, creating better production efficiency. Therefore, it can be recommended that diets containing 150mg/k astaxanthin be used in warm water fish farming.