背角无齿蚌在低盐度环境下的适应性及摄食率初步研究

Preliminary Study on the Adaptability and Feeding Rate of Anodonta woodiana in Low Salinity Environment

摘要: 为探索背角无齿蚌(Anodonta woodiana)在不同环境条件下生理响应，对背角无齿蚌在不同温度(25℃、30℃)、盐度条件(0、2.5、5、10)下的生理活动和摄食率进行了观察与比较。实验结果发现，在25℃条件下，盐度为0、2.5、5时，背角无齿蚌成贝存活率为100%；盐度10时，24 h存活率77%，48 h存活率62%；在30℃条件下，盐度0时，24h存活率为42%，盐度2.5时，24 h存活率为29%，盐度5时，24 h存活率为0，盐度10时，24 h存活率为0，各试验盐度下48 h存活率为0。实验结果表明，在25℃条件下，各盐度组的个体存活率都显著高于30℃实验组(P < 0.05)。25℃和30℃下，随盐度升高，背角无齿蚌的摄食率呈现先增长后下降的抛物线趋势，最适盐度为2.5。且相同盐度下，25℃时蚌的摄食率比30℃高。因此，背角无齿蚌适宜生存的盐度范围为0~5，25℃时背角无齿蚌包括摄食在内的生理状态优于30℃时，盐度2.5时出现最大摄食率，背角无齿蚌受温度的影响要显著高于盐度的影响。

Abstract: In order to explore the physiological response of Anodonta woodiana under different environmental conditions, the physiological activities and ingestion rates of Anodonta woodiana under 2 tempera-ture levels (25˚C, 30˚C) and 4 salinity grids(0, 2, 2.5, 5,10) were observed and compared. The results showed that the survival rate of Anodonta woodiana was 100% at 25˚C in the salinity of 0 and 2.5 and 5; when the salinity is 10, the 24 h survival rate was 77% and the 48 h survival rate was 62%. When the temperature was set at 30˚C, the survival rate was 42%(in fresh water), 29%(salinity of 2.5) and 0(salinity of 5 and 10) respectively after 24 h, and the survival rate was all 0 after 48 h at 4 levels of salinity. Under each test salinity, the survival rate of individuals in the 25˚C experimental group was significantly higher than that in the 30˚C experimental group (P < 0.05). At 25˚C and 30˚C, ingestion rates increased with increasing salinity, reaching peak levels when the salinity increased to a certain point, then dropped following increasing salinity. At a salinity of 2.5, the ingestion rates reached its peak. And at the same salinity, the ingestion rates were higher at 25˚C than at 30˚C. Therefore, the salinity range of Anodonta woodiana is 0~5. The physiological state of Anodonta woodiana at 25˚C, including ingestion, is better than that at 30˚C, and the maximum ingestion rates occur at a salinity of 2.5.