OPTIMUM SUPPLEMENTAL LEVEL OF L-ASCORBYL-2-PHOSPHATE-MG TO DIET FOR WHITE SHRIMP PENAEUS-VANNAMEI

A stable form of ascorbic acid, L-ascorbyl-2-phosphate-Mg (APM), was t ested to confirm the effect of APM on juvenile shrimp P. vannamei and determine the optimun supplemental level to diet. Shrimp, weighing 1.1 0+/-0.15 g, were fed 5 diets containing graded levels of supplemental APM (0, 10, 18, 33, and 66 mg/100 g diet) for 18 weeks. Shrimp fed the unsupplemented diet showed deficiency symptoms such as high mortality , molting frequency reduced, and blackened lesions under the exoskelet on, on the abdomen, on the carapace, in the gills and in the foregut. These symptoms were similar to the proposed ascorbic acid deficiency s ymptoms which is named ''black death.'' The results of the feeding tri als indicated that the supplementation of 10 mg APM per 100 g diet was sufficient for a better survival and prevention of clinical signs of vitamin C deficiency symptom in P. vannamei.