盐度对长江口3种滤食性贝类滤水率、摄食率、同化率的影响

采用实验生态学方法研究了盐度对长江口缢蛏(Sinonovacula constricta)、河蚬(Corbicula fluminea)和光滑河蓝蛤(Potamocorbula laevis)滤水率、摄食率、同化率的影响。缢蛏组设6个盐度梯度(5,10,15,20,25,30),光滑河蓝蛤组设6个盐度梯度(5,10,15,20,25,30),河蚬组设6个盐度梯度(0,5,10,15,20,25),并测定了此3种滤食性贝类的生物学参数。结果显示,3种滤食性贝类的滤水率、摄食率和同化率随着盐度的上升而增加,当上升到一定盐度时达到峰值,然后随着盐度的升高而降低。盐度20时,缢蛏滤水率、摄食率和同化率达到峰值,分别为0.57L/h、5.38mg POM/h和0.72%。盐度10时,光滑河蓝蛤滤水率和同化率达到峰值,分别为0.46L/h和0.53%,摄食率在盐度15时达到峰值3.80mg POM/h。盐度5时河蚬滤水率和摄食率都达到峰值,分别为0.39 L/h和2.48 mg POM/h,同化率在盐度0时已达到峰值0.51%,并随盐度上升而下降。上述结果表明,盐度对3种滤食性贝类的3个摄食生理指标均有显著影响。

Effects of salinity on filtration, ingestion, and assimilation rates of three filter-feeding bivalves in the Yangtze River estuary

The effects of salinity on the filtration, ingestion, and assimilation rates of three filter-feeding bivalves in the Yangtze River estuary were evaluated using indoor experimental ecological methods. Groups of Sinonovacula constricta and Potamocorbula laevis were each set up in six salinity grids (5, 10, 15, 20, 25, and 30), and Corbicula fluminea was set up in different six salinity grids (0, 5, 10, 15, 20, and 25). The biological parameters of these bivalves were measured. The results showed that their filtration, ingestion, and assimilation rates increased with increasing salinity, reaching peak levels when the salinity increased to a certain point, then dropped following increasing salinity. The filtration, ingestion, and assimilation rates of S. constricta reached peak levels at a salinity of 20, giving values of 0.57 L/h, 5.38 mg/h, and 0.72%, respectively. The filtration and assimilation rates of P. laevis reached peak levels at a salinity of 10, giving values of 0.46L/h and 0.53%, respectively, and the ingestion rate reached a peak level of 3.80 mg/h at a salinity of 15. The filtration and ingestion rates of C. fluminea reached peak levels at a salinity of 15, giving values of 0.39 L/h and 2.48 mg/h, respectively, and the assimilation rate reached a peak level of 0.51% at a salinity of 0 and dropped following increasing salinity. The above results indicate that salinity has a large impact on the three feeding physiology indexes of the three filter-feeding bivalves.