氨氮对墨吉明对虾的急性毒性及对其免疫因子的影响

Acute toxicity of ammonia-N and its effect on the immune parameters of Fenneropenaeus merguiensis

采用静水毒性试验方法研究氨氮对墨吉明对虾(Fenneropenaeus merguiensis)急性毒性及免疫因子的影响,旨在为墨吉明对虾健康养殖提供理论依据.实验结果表明:在海水温度26℃,盐度22,p H值8.3条件下,氨氮毒性效应与浓度和胁迫时间呈正相关.氨氮对墨吉明对虾24、48、96 h的半致死浓度分别为67.680、62.950、35.310 mg/dm3,安全浓度为3.531 mg/dm3.对应的非离子氨半致死浓度分别为6.230、5.800、3.250 mg/dm3,安全浓度为0.339 mg/dm3.在浓度为35.310 mg/dm3氨氮胁迫下,实验组墨吉明对虾血淋巴蛋白含量显著低于对照组血淋巴蛋白含量(p<0.05),但实验组墨吉明对虾血淋巴中蛋白含量会随氨氮胁迫时间延长有所恢复,96 h蛋白含量升高为(3.78±0.95)mg/cm3.氨氮胁迫下实验组对虾肝胰脏中超氧化物歧化酶(SOD)活性低于对照组,且差异水平达显著水平(p<0.05),实验组SOD活力随氨氮胁迫时间延长逐渐降低,96 h SOD活力低至(6.74±0.53)U/cm3.相反在氨氮胁迫下实验组溶菌酶活力显著高于对照组溶菌酶活力,且随胁迫时间延长逐渐降低,96 h溶菌酶活力低至(51.53±4.41)U/cm3.表明高氨氮胁迫对墨吉明对虾免疫因子产生重要影响.

Using the biological toxicity method,we studied the acute toxicity of ammonia-N and its effect on the immue parameters of Fenneropenaeus merguiensi,in order to provide the theoretical basis for the Fenneropenaeus merguiensis healthy breeding. The results showed that the toxicity of ammonia-N has a significant positive correlation with stress time and concentration. The 24,48 and 96 h LC50 was 67. 680,62. 950 and 35. 310 mg / dm^3,respectively,and the safe concentration reached at 3. 531 mg / dm^3. Under the same concentration,24,48 and 96 h LC50 of non-ionic ammonia was 6. 230,5. 800,and 3. 250 mg / dm^3,respectively,and the SC was 0. 339 mg /dm^3. Under the stress of ammonia-N（ 35. 310 mg / dm^3）,the serum protein content of the shrimp in the treated group was significantly lower than the control group（ p 0. 05）. However,the protein content recovered gradually with the stress time prolonged and it reached the maximum（ 3. 78 ± 0. 95） mg / cm^3 in the group of 96 h. The superoxide dismutase（ SOD） activity in the treated group was always lower than control group,as the time went on,it gradually declined to the lowest（ 6. 74 ± 0. 53） U / cm^3 in the group of 96 h. The activities of lysozyme was higher in the treated group,but with ammonia-N stress time prolonged,lysozyme activity decreased graduated to the lowest（ 51. 53 ±4. 41） U / cm^3 in 96 hours. Acute toxicity results suggested that the immune parameters could be severely affected by high ammonia-N stress.