日本沼虾对碱性湖泊水含盐量的适应性研究

Adaptability of Macrobrachium nipponense to Salinity of Alkaline Lake in Northeast China

采用室内急性毒性实验法,研究日本沼虾对东北地区碱性湖泊水含盐量的适应能力,探讨碱性湖泊增殖与养殖日本沼虾的可能性。结果表明,在pH为7.72～7.81、碱度7.87～14.49mmol/L时,含盐量对幼虾毒性作用的24h半数有效浓度为3.17g/L,95%置信限3.02～3.32g/L。在pH为7.85～8.07、碱度16.97～26.96mmol/L时,含盐量对幼虾毒性作用的24h、48h、96h半数致死浓度分别为7.95、6.84、5.77g/L,95%置信限分别为7.74～8.11、6.69～6.99、5.59～5.93g/L。日本沼虾对东北地区碱性湖泊水含盐量的适应上限为3.69g/L,耐受限8.65g/L,耐受范围4.25～8.19g/L,长期生存所适应的含盐量为1.52g/L。碱性水环境下日本沼虾对含盐量的适应能力将下降。东北地区含盐量在4.0g/L以下、碱度在10～30mmol/L的碱性湖泊可以增殖与养殖日本沼虾。

To understand the feasibility of artificial cultivating and proliferating freshwater shrimp Macrobrachium nipponense in alkaline lakes of northeast China, adaptive capacity of juvenile shrimp to salinity of alkaline lake was determined with enriched water of natural alkaline lake by one-way acute toxicity test in indoor. The results showed that the median effect concentration （EC50 （with 95% confidence intervals）for 24 hours of salinity to juvenile shrimp was 3.17 （3.02-3.32）g/L at pH of 7.72-7.81 and at alkalinity of 7.87- 14.49 mmol/L. At pH of 7.85-8.07 and at alkalinity of 16.97-26.96 mmol/L, the median lethal concentration （LC50 （with 95% confidence intervals）for 24, 48 and 96 hours of salinity to juvenile shrimp were 7.95 （7.74-8.11）, 6.84（6.69-6.99） and 5.77 （5.59-5.93） g/L, respectively. The safe concentration （SC）of salinity to juvenile shrimp was 1.52 g/L. lower limit of EC for 24 hours of salinity to juvenile shrimp was 2.08 g/ L, upper limit of salinity of 3.69 g/L was for juvenile shrimp living, and the range of tolerance was 4.25- 8.19 g/L. Adaptive capacity of M. nipponense to the salinity will be a decline in alkaline water. In northeast China, artificial cultivating and proliferating freshwater shrimp M. nipponense may be in alkaline lakes with the salinity under and the alkalinity of 10-30 mmol/L, and that is safe in alkaline lakes with the salinity under 1.5 g/L and the alkalinity under 10 mmol/L.