The increased input of nutrients into biological systems has been shown to result in altered biotic interactions through changes in food availability. The aim of this study was to test for an association between phytoplankton nutrient content and epibiont variables in natural zooplankton populations. Via a field survey, we studied how a gradient in food quantity and quality impacted host population density and epibiont variables in Daphnia pulex . We found a significant decrease in epibiont prevalence and infracommunity richness, which could mainly be attributed to a changing phytoplankton N : P ratio (caused by P‐limitation). We performed a lab experiment in which we exposed Daphnia magna to different algal nutrient ratios and the epibionts detected in the field study. P‐limitation in the algae affected D. magna performance and resulted in similar trends of food quality effects in the epibiont variables. The experiment, however, also reflected subtle differences between different epibiont species.

中文翻译：

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食物营养供应影响天然水蚤种群中表生菌的流行和丰富度

已经证明，增加生物系统的营养输入会通过食物供应的变化导致生物相互作用的改变。本研究的目的是测试天然浮游动物种群中浮游植物营养成分与表生变量之间的关联。通过实地调查，我们研究了食物数量和质量的梯度如何影响 Daphnia pulex 的寄主种群密度和表生变量。我们发现表皮生物流行率和群落群落丰富度显着下降，这主要归因于浮游植物 N:P 比率的变化（由 P 限制引起）。我们进行了一项实验室实验，在该实验中，我们将大型水蚤暴露于不同的藻类营养比例和实地研究中检测到的表生菌中。藻类中的 P 限制影响 D. magna 性能，并导致表皮变量中食品质量影响的类似趋势。然而，该实验也反映了不同表生物种之间的细微差异。