Interaction between taurine, vitamin E and vitamin C in microdiets for gilthead seabream (Sparus aurata) larvae

The negative effects of oxidative damage on larval development, growth and survival are among the factors markedly affecting marine fish larvae production success. Whereas alpha-tocopherol (vit E) and L-ascorbic acid (vit C) are strong antioxidants, the potential antioxidant role of taurine (Tau) in fish diets and its relation with other antioxidant nutrients needs further clarification. The present study aimed to determine the potential interactions between the dietary levels of vit E plus vit C and Tau on survival, growth, bone development and oxidative metabolism in gilthead seabream larvae. Six micro-bound diets containing two levels of Tau combined with three levels of vit E plus vit C were manually fed 24 times/day to 16 dph larvae for 15 days. Elevation of dietary vit E and vit C over 3000 mg/kg, led to unbalanced body vit C/vit E ratio and up-regulation of genes coding for antioxidant enzymes, the highest incidence of bone anomalies and the lowest larval survival. Increase in dietary vit C + vit E up to 1800 mg/kg, down-regulated GPX expression, up-regulated OC expression and reduced maxillary bone anomalies. Increase in dietary Tau up to 7.1 g/kg significantly improved larval growth, down-regulated antioxidant enzyme genes and reduced the incidence of bone anomalies. Moreover, the pro-oxidative effects of the high supplementation of vit C and E where mitigated by increase in dietary Tau levels. Finally, increase in dietary vit E, vit C and Tau up to 1783 mg/kg, 1921 mg/kg and 7 g/kg lead to the highest larval survival and growth, the highest OC gene expression and the lowest incidence of bone anomalies, including lordosis, kyphosis, branchiostegal and maxillary bones anomalies.