Pyridoxine Requirement of Juvenile Abalone, Haliotis Discus Hannai Ino (Report‪)‬

ABSTRACT Juvenile abalone, Haliotis discus hannai Ino (initial mean body weight: 0.56 [+ or -] 0.01 g, shell length: 15.74 [+ or -] 0.13 mm) were fed six diets with graded levels of pyridoxine (PN) (0.40, 12.5, 22.7, 43.5, 87.8, and 172.2 mg/kg diet). Each diet was fed to three replicate groups of juvenile abalone for 16 wk. Dietary PN significantly (P 0.05) affected abalone growth, tissue concentrations of PN and pyridoxal 5'-phosphate (PLP), and the activities of asparatate aminotransferase (AST) and alanine aminotransferase (ALT). The responses of all these parameters to dietary pyridoxine levels fitted the broken-line model. Brokenline regression analyses showed that the breakpoints were 23 on the basis of growth data, 32-38 on tissue concentrations of PN and PLP, 20-21 on the activities of visceral AST and A LT, and 39-40 on the activities of muscle AST and ALT. Hence, the requirement of H. discus hannai for dietary pyridoxine should be 23 mg/kg diet for maximum growth, and about 40 mg/kg diet for the saturation of tissue PN and PEP, or tissue aminotransferase activities. KEY WORDS: abalone, Haliotis discus hannai, pyridoxine, requirement, aminotransferases, feeding and nutrition