中文摘要：

水体氨氮含量过高是中华鳖养殖过程中经常遇到的问题,本实验探讨了慢性氨氮暴露环境对中华鳖幼鳖生长及非特异性免疫功能的影响.挑选64只初始体质量为（90.5±20.5）g的健康中华鳖幼鳖分别暴露于非离子氨氮（UIA-N）质量浓度为1.5（Cl）,2.6（C2）和4.1（C3）mg·L^-1的水环境中,每组16只,暴露时间为42 d.对照组（C0）用不加外源氨氮的自然晾晒自来水饲养.实验期间温度（（29士0.5）℃）和pH值（7.75±0.1）在各组间保持一致.结果表明,本实验所设氨氮的质量浓度梯度对特殊生长率、补体旁路途径介导的血清溶血活性和血清杀菌活性都没有显著影响（P＞0.05）,但血清溶菌活性和血细胞吞噬率这2个指标在C1组和C2组显著升高（P＜0.05）,同时其他各处理组与对照组间未见显著差异（P＞0.05）.由此推论：低于4.1 mg·L^-1UIA-N的水环境对中华鳖的生长和非特异性免疫功能没有明显的抑制作用,对某些指标甚至有刺激升高的作用,表明中华鳖具有较强的耐受水体中高质量浓度氨氮的能力.

英文摘要：

The soft-shelled turtles are often exposed to high ambient ammonia levels in intensive rearing conditions. The effects of chronic ammonia exposure on growth and nonspecific immune parameters in juvenile Chinese soft-shelled turtle, Pelodiscus sinensis are evaluated. 64 healthy turtles with identical body weight （Body weight： （90. 5±20. 5） g） are submitted to three ammonia concentrations, 1.5（C1）, 2. 6（C2） and 4. 1 （C3） mg·L^-1 unionized ammonia-N （UIA-N） for 42 days. A control group （CO） is also set in which the animals are reared in tap water with no extrinsic NH4Cl added. Consistent ambient temperature （（29. 5±0. 5） ℃） and pH（7. 75 ± 0. 10） in each treatment are maintained throughout the experiment. Over the ammonia range set in the present study, no significant differences of specific growth rate （SGR）, serum hemolytic activities, and serum bactericidal activity are observed. But serum bacteriolytic activity and whole blood phagocytic rate are significantly enhanced in group C1 and C2 respectively. The present results indicate that the turtle has adapted to ambient ammonia set in the present study and is fairly resistant to high ambient ammonia levels.