Gopko M, Mironova E, Pasternak A, Mikheev V, Taskinen J
A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences,Leninskij prosp.,33, 119071 Moscow,Russia.
Institute of Cytology of the Russian Academy of Sciences,Tikhoretsky Ave.,4, 194064 Saint Petersburg,Russia.
Parasitology. 2017 Dec;144(14):1971-1979. doi: 10.1017/S0031182017001421. Epub 2017 Aug 2.
Recent results suggest that bivalves can play an important role in restraining the spread of various aquatic infections. However, the ability of mussels to remove free-living stages of macroparasites and reduce their transmission is still understudied, especially for freshwater ecosystems. We investigated the influence of the common freshwater mussel (Anodonta anatina) on the transmission of a trematode (eye fluke, Diplostomum pseudospathaceum), which frequently infects fish in farms and natural habitats. In our experiments, mussels caused a significant decrease (P < 0·001) in the abundance of trematode free-living stages, from 6520 to 1770 cercariae L-1 on average (about 4-fold in 2 h). Individual clearance rates of mussels were 0·6‒3·7 L per hour (mean 1·9). These tests were followed by experimental infections of rainbow trout (Oncorhynchus mykiss) with different doses of D. pseudospathaceum cercariae in the presence or absence of mussels. Exposure of fish to cercariae in the presence of mussels significantly (P < 0·05) reduced the infection intensities in fish (by 30-40%) at all exposure doses. Our results indicate that freshwater bivalves can markedly reduce local cercariae densities and could be useful in mitigation of trematodoses harmful to fish farming.
近期研究结果表明，双壳贝类在抑制各种水生感染的传播方面可发挥重要作用。然而，贻贝清除大型寄生虫自由生活阶段并减少其传播的能力仍未得到充分研究，尤其是在淡水生态系统中。我们调查了常见淡水贻贝（Anodonta anatina）对一种吸虫（眼吸虫，Diplostomum pseudospathaceum）传播的影响，这种吸虫经常感染养殖场和自然栖息地中的鱼类。在我们的实验中，贻贝使吸虫自由生活阶段的数量显著减少（P < 0·001），平均从6520尾尾蚴每升降至1770尾尾蚴每升（2小时内约为4倍）。贻贝的个体清除率为每小时0·6 - 3·7升（平均1·9）。这些测试之后，在有或没有贻贝的情况下，用不同剂量的拟锥双腔吸虫尾蚴对虹鳟（Oncorhynchus mykiss）进行实验性感染。在有贻贝存在的情况下，鱼接触尾蚴显著（P < 0·05）降低了所有接触剂量下鱼的感染强度（降低了30 - 40%）。我们的结果表明，淡水双壳贝类可显著降低当地尾蚴密度，并且在减轻对养鱼业有害的吸虫感染方面可能有用。
