Immunomodulation by dietary beta-1, 3-glucan in the brooders of the black tiger shrimp Penaeus monodon

The present study evaluated the effectiveness of beta-1,3-glucan derived fr om Schizophyllum commune in enhancing shrimp survival as well as haemocyte phagocytosis and superoxide anion production in brooder Penaeus monodon. Po nd-reared P. monodon adults (135 +/- 25 g) stocked in outdoor or indoor tan ks were fed either a test diet containing beta-1,3-glucan (2.0 g kg(-1)) or a glucan-free control diet for 40 days. Their survival was compared. The b rooders reared in indoor tanks were analysed at days 0, 1, 3, 6, 12, 24, 30 and 40 for their haemocyte phagocytic activity and superoxide anion produc tion. The results showed that regardless of indoor or outdoor rearing the s urvival rate of shrimp fed the glucan diet was significantly higher (P<0.00 1) than that of the control group. The brooders showed enhanced haemocyte p hagocytic activity, cell adhesion and superoxide anion production when gluc an was administered in their diets. The immunostimulatory enhancement peake d at day 24 after starting the dietary exposure and subsequently decreased to the pre-feeding level at the end of the 40 days feeding trial. (C) 2000 Academic Press.