The toxicity of ammoniaN on Penaeus monodon and immune parameters

Abstract:

The results of acute toxicity test of ammonia-N on Penaeus monodon carried out by biological toxicity test showed that effect of toxicity has a significant positive correlation with the ammoniaN maintained time and concentration. In the condition of seawater 30℃, pH=8, S=34.5, the half lethal concentration of ammoniaN were 52.63 mg/L, 39.68 mg/L, 31.65 mg/L and 29.94 mg/L, lasting for 24 h, 48 h,72 h and 96 h respectively, and the safe concentration was 2.99 mg/L. In the same concentration , half lethal concentration of nonionic ammonia were 3.23 mg/L, 2.43 mg/L, 1.94 mg/L, 1.84 mg/L respectively and the safe concentration was 0.18 mg/L. The effect of ammonia-N level of 29.9 mg/L on immune parameters of Penaeus monodon showed the variation trend of different immune parameters :including activity of phenoloxidase (PO) decreasing in the whole of study, superoxide dismutase (SOD) and peroxidase (POD) activity in serum increasing at first after ammonia-N stimulated and then decreasing, acid phosphatase (ACP) activity increasing at first after ammoniaN stimulated, then decreasing and increasing at last within 96h. ANOVA indicated that the activities of PO, SOD, POD, ACP in eight sampling points(0 h, 4 h, 8 h, 12 h, 24 h, 48 h, 72 h, 96 h) had significant difference (P< 0.01), while the control groups all had no significant difference (P> 0.05). Acute toxicity result, changes of different immune parameters in high ammonia-N stress and influence of high ammonia on the immune system obtained in this study provide a scientific basis for the healthy development of culture of Penaeus monodon.