Limited synergistic effect of dietary Spirulina on vitamin C nutrition of red sea bream Pagrus major

One-year-old red sea bream Pagrus major (70 g body weight) were fed a moist diet containing 2.5% Spirulina sp, meal and/or two types of ascorbate for 81 days, The effects of these diets were evaluated in terms of tissue ascorbate content, serum parameters, and hepatic enzyme activities, Coexistence of Spirulina and ascorbate improved body weight gain, feed efficiency, and digestibility. Spirulina protected ascorbic acid in the diet from degradation. Spirulina significantly elevated ascorbate levels in serum and the hepatopancreas. Depression of lipoperoxide and nonesterified fatty acids in serum would be due to multiplier effects of Spirulina and ascorbate. Activities of hepatic lipogenic enzyme (NADP-isocitrate dehydrogenase) and amino acid-degrading enzyme (arginase) were significantly depressed by coexistence of Spirulina and ascorbate. The results indicated limited synergistic effects of dietary Spirulina on vitamin C nutrition in red sea bream.