Abstract

Invasions of alien species of mollusks are of great interest as a result of their serious environmental and economic consequences. We present new information on the distribution and quantitative characteristics of mollusks from the genus Dreissena in one of the tributaries of the Kuybyshev Reservoir. The fact of the penetration of these species up to the upper reaches of the Sviyaga River has been revealed. The quantitative values of the Dreissena vary unevenly, gradually increasing toward the mouth of the river. Native species of mollusks dominate in the upper and middle reaches of the river, and alien ones in the lower reaches. The comparison of morphometric characteristics of shells in the river revealed significant differences between two related dreissenid species, with the exception of the river mouth. The important factors in the distribution and development of two species of Dreissena in the Sviyaga River are flow rate, depth and width of the river section, and the absence of a solid substrate in the water.

中文翻译：

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伏尔加河中游水库大支流Dreissena外来软体动物空间分布特征（以斯维亚加河为例）

摘要

由于其严重的环境和经济后果，外来软体动物物种的入侵引起了极大的兴趣。我们提供了有关 Kuybyshev 水库一条支流中Dreissena属软体动物分布和数量特征的新信息。这些物种渗透到 Sviyaga 河上游的事实已经被揭露。Dreissena的定量值变化不均，向河口逐渐增加。河中上游以本土软体动物为主，下游以外来物种为主。河中贝壳形态特征的比较揭示了两种相关的德氏贝类之间的显着差异，河口除外。斯维亚加河的两个Dreissena种分布和发育的重要因素是流速、河段的深度和宽度以及水中没有固体底物。