Effect of Ammonia Exposure on the Non-Specific Immunity of Fresh Water Pearl Mussel Hyriopsis cumingii

Abstract

Ammonia-N, the principal end-product of protein catabolism, is an important environmental toxic factor in ponds. Elevated environmental ammonia-N is very toxic to aquatic animals and has a deleterious effect on their immune system. However, its effect on their immune system remains unclear. In this study, the effects of ammonia-N (0, 5, 10 and 30 mg/L) on immune responses of Fresh Water Pearl Mussel Hyriopsis cumingii were determined. When exposed to 5 mg/L ammonia-N lysozyme activity increased significantly. Superoxide dismutase activity was highest in the 5 mg/L group followed by the 10 mg/L group. The marked decrease of Lysozyme activity of Fresh Water Pearl Mussel Hyriopsis cumingii in 10 mg/L and 30 mg/L ammonia-N groups suggests that the higher concentrations of ammonia-N reduces or inhibits their non-specific immunity. Compared to the control group, superoxide dismutase activity in 30 mg/L ammonia also decreased significantly. When exposed to 5mg/L ammonia-N, catalase, acid phosphatase and alkaline phosphatase activity enhanced. In the 10 mg/L and 30 mg/L group, ammonia-N decreased significantly The lysozyme, catalase, acid phosphatase and alkaline phosphatase activity showed a similar tendency. This suggests that in H. cumingii immunostimulatory response is enhanced at low ammoniaN concentrations. The results of this study provide a theoretical basis for disease prevention in the freshwater pearl mussel.