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以脊尾白虾(Exopalaemon carinicauda)糠虾幼体为实验材料,用氯化铵模拟水体中氨氮进行毒性试验。结果表明,氨氮对糠虾幼体24、48、72和96 h的半致死浓度(LC50)分别为27.51、23.15、19.46和10.28 mg/L。糠虾幼体体内毒性蓄积程度随实验时间逐步增强。在6 d的糠虾幼体蜕壳变态的亚急性实验中,高浓度的氨氮表现出较明显的抑制作用,显示剂量效应关系。此外,氨氮对脊尾白虾糠虾幼体肌肉组织细胞的核酸代谢及DNA合成有一定的影响,高浓度的氨氮促进RNA/DNA的含量比值有所下降,与对照组相比,差异性较显著。实验显示,在一定氨氮浓度胁迫下,糠虾幼体变态率与RNA/DNA的比值呈现较显著的指数负相关性的关系,说明了糠虾幼体本身的生长代谢过程还是受到了氨氮的抑制作用。
The experiment was conducted on the larvae of Exopalaemon carinicauda, using ammonium chloride to simulate the toxicity of ammonia in water. The results showed that the LC50 values of ammonia nitrogen to the juveniles of Mysis were 27.51, 23.15, 19.46 and 10.28 mg / L at 24, 48, 72 and 96 h, respectively. The degree of accumulation of toxicity in the shrimp was gradually increased with the experiment time. In the sub-acute experiment of 6-day-old molting of mollusk prawn larvae, the high concentration of ammonia nitrogen showed a more obvious inhibitory effect and showed a dose-response relationship. In addition, ammonia nitrogen had some effects on the nucleic acid metabolism and DNA synthesis of Muscle tissue cells of M. molitoriana, and the ratio of RNA / DNA increased with high concentration of ammonia nitrogen. Compared with the control group, the difference was significant. Experiments show that under certain ammonia nitrogen concentration stress, the relationship between the metamorphosis rate and the ratio of RNA / DNA showed a significantly negative exponential relationship, indicating that the growth and metabolism of M. shrimp larvae were still inhibited by ammonia nitrogen.