Effects of dietary calcium levels on growth and tissue mineralization in Japanese seabass, Lateolabrax japonicus

A feeding trial was conducted to investigate the effects of different levels of calcium (Ca) on growth and tissue mineralization in Japanese seabass, Lateolabrax japonicus. Six experimental diets were formulated to contain different levels of Ca (2.9, 4.2, 6.5, 7.9, 10.2 and 31.0gkg(-1)) from dietary ingredients and Ca-lactate5H(2)O. The diets were fed to three triplicate groups of Japanese seabass (initial weight, 12.5 +/- 0.0g) for 56days. Dietary Ca had no significant effect on survival or feed efficiency; however, the highest Ca (31.0 g kg(-1)) diet significantly reduced weight gain, feeding rate and whole-body and muscle protein and lipid contents, as well as serum Ca concentration and alkaline phosphatase activity. A significant reduction in vertebral Ca, P, Zn, Fe and Mn contents and scale Ca, P, Mg and Mn contents was observed in Japanese seabass as dietary Ca level increased. Deformed fish were primarily found in the 2.9 and 31.0 g Ca kg(-1) groups, indicating that these fish had poor bone mineralization.