Abstract

At the beginning of the dry season, immediately after the end of the rainy season, estimations of zooplankton abundance have been carried out in three types of shore areas of Lake Tana (Ethiopia): (1) open water, (2) borders of thickets, and (3) macrophyte thickets. The minimum quantitative characteristics of plankton animals are reported in macrophyte thickets; the maximum are in areas of open water. Negative correlations are obtained between the level of overgrowth by macrophytes and the quantitative characteristics of zooplankton organisms. The peculiarities of the quantitative development and structure of zooplankton in the zone of thickets and at their border, when compared with open water areas (as well as compared with the second half of the dry season), indicate the leading role of top-control in the formation of invertebrate communities, which is associated with an increase in the number of young fish. Optimal conditions for feeding and shelters for juvenile fish during daylight hours are formed at the boundary of macrophyte thickets, as a result of which the minimum abundance and biomass of zooplankton are found there.

中文翻译：

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旱季开始时在塔纳湖岸带（埃塞俄比亚）的浮游动物

摘要

在干旱季节开始时，在雨季结束之后，立即在塔纳湖（埃塞俄比亚）的三种类型的海岸地区进行了浮游动物丰度的估算：（1）开阔水域，（2）灌木丛边界，和（3）大型植物灌木丛。大型植物灌丛中报告了浮游生物的最低定量特征。最多的是开放水域。大型植物过度生长的水平与浮游生物的数量特征之间存在负相关关系。与开放水域（以及与旱季的后半期相比）相比，在灌丛区及其边界的浮游动物的定量发育和结构的特殊性，表明了顶部控制在浮游生物中的主导作用。无脊椎动物社区的形成，这与幼鱼数量的增加有关。在大型植物丛的边界形成了白天幼鱼觅食和庇护的最佳条件，因此在那里发现了浮游生物的最低丰度和生物量。