Effect of dietary supplementation with taurine, β-alanine and GABA on the growth of juvenile and fingerling Japanese flounder Paralichthys olivaceus

Three diets supplemented with taurine, beta-alanine and GABA and a control diet were fed to juvenile and fingerling Japanese flounder to investigate the effects of the diets on growth and metabolic changes of free amino acids in whole body and tissues. In experiment I, three diets supplemented with 1% each of taurine, beta-alanine and GABA and a control diet were fed to juvenile Japanese flounder with an initial mean body weight of 0.4 g for 4 weeks at 20degreesC. In experiment II, the taurine-supplemented diet and a control diet were fed to fingerling Japanese flounder with an initial mean body weight of 15 g for 4 weeks at 20degreesC. Only supplementation of taurine in the diet of juvenile flounder improved their growth performance in experiment I, but fingerling growth performance of experiment II was not significantly related to taurine supplementation in the experimental diet. These results suggest that there is a greater requirement for taurine for the growth of juvenile Japanese flounder than fingerling Japanese flounder.