中文摘要：

以NHtCI为主要成分配比成不同浓度的氨溶液，以Y型水迷宫为水环境的选择实验装置，从克氏原螯虾的行为学角度出发，探究其对不同浓度氨溶液的趋避选择性。实验共设置5个浓度梯度：4．750、7．125、9．500、14．250和19．000mg／L，其pH值为7．0，水温为20±0．5℃。以体长为5．01±0．43cm的克氏原螯虾亚成体及体长为0．75±0．15cm的幼体为实验对象，在Y型水迷宫中的两个选择区中分别放人污水和清水，供实验虾进行选择，记录选择清水和污水的次数及未作出选择的次数，对数据进行非参数检验的二项分布检验。结果表明亚成体在氨浓度4．750、7．125、9．500及14．250mg／L时，没有明显选择性，在氨浓度19．000mg／L时，显著避开污水；幼虾在氨浓度4．750mg／L时，没有明显选择性，在氨浓度7．125和9．500mg／L时，显著避开污水，当氨浓度达到14．250mg／L及以上时，出现中毒症状，丧失选择能力。该结果证明克氏原螯虾对高浓度的氨氮型污水不仅没有偏好，而且当浓度达到一定数值时会主动躲避，或躲避不及发生行为异常乃至死亡。

英文摘要：

This experiment used NH4Cl for the main constituent to prepare ammonia solutions and a Y shape water maze for experiment equipment. Our purpose was to find out the selection of Procambarus clarkii of different ammonia concentration from the ethological point of view. Five concentrations of 4. 750, 7. 125,9. 500,14. 250 and 19. 000 mg/L were set. Their pH value was 7.0,the temperature was 20±0.5℃. P. clarkii sub-adult of 5.01±0. 43 cm in body length and juvenile of 0. 75±0. 15 cm in body length were used for the experiment. Ammonia solution and clean water were put in the 2 selection areas of a Y shape water maze, then let the crayfish choose, the times of selection of ammonia solution, clean water and no selection were recorded. Binomial test of nonparametric tests to calculate the data was carried out. The result indicated that the sub-adults had no selection at the ammonia concentration of 4. 750, 7. 125,9. 500 and 14. 250 mg/L,but they significantly avoided the ammonia solution with concentration of 19. 000 mg/L;the juveniles had no selection at the ammonia concentration of 4. 750 mg/L,but they significantly avoided the ammonia solution when the ammonia concentration is 7. 125 and 9. 500 mg/L,and they had toxic symptom and lost the ability of selection when the ammonia concentration is 14. 250 and 19. 000 mg/L. The study in- dicated that P. clarkii has no preference for ammonia solution and will avoid the ammonia solution when the concentration reaches the right value or even die when they can＇t avoid in time.