Effect of dietary minerals in early weaning diets on growth, survival and gene expression of gilthead sea bream (Sparus aurata) larvae
International Symposium on Fish Nutrition and Feeding 2016, Idaho, United States Of America, 5 - 10 June 2016, pp.13, (Full Text)
- Publication Type: Conference Paper / Full Text
- City: Idaho
- Country: United States Of America
- Page Numbers: pp.13
- Istanbul University Affiliated: Yes
Abstract
Despite the importance of trace mineral for the normal development of marine fish larvae, previous studies have demonstrated that the contents of this nutrients in live preys used in larviculture are much lower than those of copepods. Moreover , our previous studies have shown the importance of a premix inclusion of Zn, Mn and Se in early weaning diets for larval growth, and suggested a potential toxicity by one of them. The objective of the present study was to determine the effect of the single dietary inclusion of Zn, Mn, Se and Cu, their combination (Control+) or their lack (Control-). These 6 diets were fed to 22 day-old gilthead seabream larvae in triplicates for three weeks. At the end of the trial, survival was significantly (P < 0.05) lowest in fish fed all these minerals (C+ diet, 17.16±7 % mean±SD), followed by that of larvae fed Mn (Mn diet, 21.91±7). The highest survival was obtained by supplementation with Cu (Cu diet, 35.27±15), followed by negative control (C- diet, 34.58±9), whereas Zn and Se supplementation produced intermediate survivals. Cu and Se significantly improved larval growth in terms of total length and body weight, in comparison to the C- fish, whereas fish fed Mn and C+ showed the lowest fish growth. No significant differences were found in the expression of Mnsod, CuZnsod or Cat, whereas Gpx was significantly up-regulated in fish fed Se and C+ diets. Fatty acid composition of the diets was homogeneous as well as that of the larvae, except for a significantly highest ARA/EPA and lowest DHA/EPA in larvae fed Cu diet and the opposite in fish fed C+ diet. The results pointed out the importance of supplementation with Cu, as well as Se and Zn on early weaning diets for gilthead seabream, and the potential toxic effect of Mn. Further studies are being conducted to determine optimum levels of these nutrients in diets for marine fish larvae.