The immune parameters and the resistance against Photobacterium damselae of tiger shrimp Penaeus monodon (14.2 ± 1.8 g) were evaluated when the shrimp were fed diets containing the acidicaqueous extract of Sargassum glaucescens (SGE) at 0 (control), 0.5, and 1.0 g/kg for 21 days. Results showed that P. monodon fed a diet containing 1.0 g/kg SGE had significantly increased phenoloxidase activity and respiratory bursts, but decreased superoxide dismutase activity (p < 0.05). The glutathione peroxidase and transglutaminase activities, clotting rate, and phagocytic activity and clearance efficiency toward P. damseale were significantly elevated in shrimp fed 0.5 and 1.0 g/kg SGE-containing diets compared to control shrimp (p < 0.05). In challenged test, the survival of shrimp fed a diet containing 1.0 g/kg SGE was significantly higher (p < 0.05) than that of control shrimp after 7 days. We therefore recommend dietary SGE administration at 1.0 g/kg to enhance the immunity and resistance against P. damselae in P. monodon.
The immune parameters and the resistance against Photobacterium damselae of tiger shrimp Penaeus monodon (14.2 ± 1.8 g) were evaluated when the shrimp were fed diets containing the acidicaqueous extract of Sargassum glaucescens (SGE) at 0 (control), 0.5, and 1.0 g/kg for 21 days. Results showed that P. monodon fed a diet containing 1.0 g/kg SGE had significantly increased phenoloxidase activity and respiratory bursts, but decreased superoxide dismutase activity (p < 0.05). The glutathione peroxidase and transglutaminase activities, clotting rate, and phagocytic activity and clearance efficiency toward P. damseale were significantly elevated in shrimp fed 0.5 and 1.0 g/kg SGE-containing diets compared to control shrimp (p < 0.05). In challenged test, the survival of shrimp fed a diet containing 1.0 g/kg SGE was significantly higher (p < 0.05) than that of control shrimp after 7 days. We therefore recommend dietary SGE administration at 1.0 g/kg to enhance the immunity and resistance against P. damselae in P. monodon.