Styrax japonica supplementation diet enhances the innate immune response in Epinephelus bruneus against bacterial and protozoan infections

► Kelp grouper fed with S. japonica diets significantly increased survival rate. ► The phagocytic activity and respiratory activity significantly increased. ► The complement activity and lysozyme activity significantly enhanced all doses diet. ► Serum bactericidal activity and total protein content significantly enhanced all doses diet. ► Antiprotease activity and myeloperoxidase levels significantly enhanced.