Shrimp shell meal in diets for large yellow croaker Larimichthys croceus: Effects on growth, body composition, skin coloration and anti-oxidative capacity

• Effects of dietary shrimp shell meal (SSM) on the large yellow croaker were studied.
• Dietary SSM significantly improved the skin coloration and skin carotenoid content.
• Low level of SSM (12%) had no negative effects on the growth and feed utilization.
• Higher level of SSM (24%) significantly reduced the growth.
• The anti-oxidative capacity was not significantly affected by SSM.

A 9-week feeding trial was conducted to evaluate the effects of dietary shrimp shell meal (SSM) on the growth performance, body composition, skin coloration and anti-oxidative capacity of large yellow croaker Larimichthys croceus. A control diet (SM0) without SSM, a diet with 12% of SSM (SM12) and a diet with 24% of SSM (SM24) were each fed to three groups of 70-g large yellow croaker. Results showed that the specific growth rate (SGR), survival rate (SR) and protein efficiency ratio (PER) in the SM24 group were significantly lower than those in the SM12 and SM0 groups (P < 0.05). The whole-body lipid content in SM24 group was significantly lower than that in the other two groups (P < 0.05). The skin coloration and carotenoid content were significantly improved with the supplementation of SSM in the diet (P < 0.05). Compared to those in the SM0 group, dorsal skin melanin content and tyrosinase activity were significantly higher in SM12 group and SM24 group (P < 0.05). The amount of thiobarbituric acid reactive substances (TBARSs), the superoxide dismutase activity (SOD) and the concentration of reduced glutathione (GSH) in the liver were not significantly affected by dietary SSM (P > 0.05). However, the total anti-oxidative capacity (T-AOC) in the SM12 group was significantly higher than that in SM0. In conclusion, dietary SSM can improve the skin coloration with no negative effects on the anti-oxidative capacity of large yellow croaker. However, high dietary SSM (24%) decreased the growth performance and whole-body lipid content.