Abstract

This paper presents recent data on the population of the anadromous vimba bream (Vimba vimba vimba), introduced in the Volga basin. After penetration to the downstream section of the Volga River from the Volgograd Reservoir, vimba bream can be found throughout the entire unregulated stretch downstream of the Volga Hydroelectric Station. Observations show that the population size changes naturally during the year owing to its spawning migration. At the same time, a gradual transformation of the seasonal dynamics of the species is observed. As populations spread further downstream, the migrations of spawners downstream of the dam become longer, and the population density decreases. Also a seasonal redistribution takes place, with reduced migration observed in autumn and increased migration during spring. Meanwhile, the growth rate in the downstream section of the Volga River is comparable to the growth rate of populations in the Volgograd and Tsimlyansk reservoirs. Spawning occurs on in-channel spawning grounds. Yearlings are observed over a distance of 100 km downstream of the dam. In addition to Vimba bream, single specimens of Caspian bream (V. v. persa) are also recorded.

中文翻译：

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伏尔加河下游无管制区的of类Vi（Vimba vimba vimba（Actinopterygii：Cyprinidae））分布

摘要

本文提供了有关无翅vi鱼（Vimba vimba vimba）种群的最新数据），在伏尔加河盆地引入。从伏尔加格勒水库渗入伏尔加河下游部分后，在伏尔加河水电站下游整个不受管制的河段中都发现了mb鲷。观察表明，由于其产卵迁移，种群数量在一年中自然变化。同时，观察到该物种的季节动态逐渐变化。随着种群进一步向下游扩散，水坝下游的产卵者迁移变得更长，种群密度降低。此外，还会发生季节性重新分配，秋季的迁徙减少，春季的迁徙增加。与此同时，伏尔加河下游段的增长率与伏尔加格勒和尖沙林斯克水库的人口增长率相当。产卵发生在通道内产卵场。在水坝下游100公里处观察到一岁。除了Vi鱼外，还有里海鱼的单个标本（V. v。persa）也被记录下来。