Abstract

In reservoirs and watercourses of the Upper Ob basin (southern Western Siberia), two representatives of the family Valvatidae (Valvatidae) of the subgenus Sibirovalvata, having a planispiral shell, have been noted. It is shown that two species of planispiral mollusks from this subgenus live in the region: Valvata (Sibirovalvata) frigida and V. (S.) sibirica. On the material from the Upper Ob basin, significant conchological differences between V. (S.) frigida and V. (S.) sibirica in regards to key morphometric indices have been noted. According to the results of a comparison with the material from the northern Western Siberia, it is found that the shells of the northern (basin of the Taz River) and southern (basin of the Upper Ob) populations of V. (S.) frigida and V. (S.) sibirica differ very slightly in morphometric indices, which indicates a slight variability of these traits within the range. At the same time, the detected significant differences between the northern and southern populations in the absolute size of the shell can presumably be explained by the conditions of specific habitats. At the same time, a more favorable temperature regime in the south may be offset by a lack of oxygen, including during the summer–autumn low water period.

中文翻译：

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鄂毕盆地上游盆地 Sibirovalvata 亚属的平面螺旋 Valvatids（软体动物：腹足纲：Valvatidae）

摘要

在上鄂毕盆地（西西伯利亚南部）的水库和水道中，有两种 Valvatidae 亚属的代表Sibirovalvata，具有平面螺旋壳，已被注意到。结果表明，该亚属的两种平面螺旋软体动物生活在该地区：Valvata (Sibirovalvata寒冷) S. (V.在关键形态指标方面已被注意到。根据与西西伯利亚北部的材料比对结果发现，北部（塔兹河流域）和南部（上鄂毕盆地）种群的贝壳西伯利亚) S. (V。和弗里吉达 (S. (V.。就鄂毕盆地上部的材料而言，西伯利亚)S.V。和弗里吉达) V。 (S.) 形态指数差异非常小，这表明这些性状在该范围内略有变化。同时，检测到的北方和南方种群在贝壳绝对尺寸上的显着差异可能可以用特定栖息地的条件来解释。与此同时，南方更有利的温度状况可能会因缺氧而被抵消，包括在夏秋季低水期。西伯利亚