Cladoceran Size and the Abundance of Ciliates and Rotifers in Freshwater Zooplankton Communities

将进行实地和实验室研究， 假设纤毛虫和轮虫将更丰富， 只有小枝藻的淡水动植物群落 物种比在那些大枝藻物种。 原位 封闭实验将测试这一假设，增加没有 枝角类，小型枝角类（Bosmina longirostris），或大型 枝角类（蚤状水蚤）的纤毛虫的自然群落 和轮虫。 这些实验将得到以下补充：1） 实验室竞争实验，以测试的能力， 轮虫Keratella cochlearis与不同大小 枝藻种; 2）实验室实验， 对各种不同的可接受性的观察- 大小的纤毛虫物种的机械干扰（损害， 捕食）从不同大小的枝藻物种。 结果 这项研究应该有助于了解 纤毛虫和轮虫在自然群落中的重要性 以及食虫鱼类的副作用， 选择性地捕食自然群落中的大型枝角类动物。 这 这项研究将是第一个广泛调查相互作用的研究。 枝角类和纤毛虫之间的关系，并评估 自然群落中纤毛虫上的枝角类。

Field and laboratory studies will be conducted to test the hypothesis that ciliates and rotifers will be more abundant in freshwater zooplandton communities with only small cladoceran species than in those with large cladoceran species. In situ enclosure experiments will test this hypothesis by adding no cladocerans, small cladocerans (Bosmina longirostris), or large cladocerans (Daphnia pulex) to natural communities of ciliates and rotifers. These experiments will be supplemented by: 1) laboratory competition experiments to test the ability of the rotifer Keratella cochlearis to coexist with different-sized cladoceran species; and 2) laboratory experiments and observations on the susceptibilities of a variety of different- sized ciliate species to mechanical interference (damage, predation) from different-sized cladoceran species. The results of this research should be useful in understanding variation in the importance of ciliates and rotifers in natural communities and secondary effects of zooplanktivorous fish, which prey selectively on large cladocerans in natural communities. This study will be the first to extensively investigate interactions between cladocerans and ciliates, and to assess the impact of cladocerans on ciliates in natural communities.