The association with microbes in plants and animals is known to be beneficial for host's survival and fitness, but the generality of the effect of the microbiome is still debated. For some animals, similarities in microbiome composition reflect taxonomic relatedness of the hosts, a pattern termed phylosymbiosis. The mechanisms behind the pattern could be due to co‐evolution and/or to correlated ecological constraints. General conclusions are hampered by the fact that available knowledge is highly dominated by microbiomes from model species. Here, we addressed the issue of the generality of phylosymbiosis by analysing the species‐specificity of microbiomes across different species of freshwater zooplankton, including rotifers, cladocerans, and copepods, coupling field surveys and experimental manipulations. We found that no signal of phylosymbiosis was present, and that the proportion of “core” microbial taxa, stable and consistent within each species, was very low. Changes in food and temperature under laboratory experimental settings revealed that the microbiome of freshwater zooplankton is highly flexible and can be influenced by the external environment. Thus, the role of co‐evolution, strict association, and interaction with microbes within the holobiont concept highlighted for vertebrates, corals, sponges, and other animals does not seem to be supported for all animals, at least not for freshwater zooplankton. Zooplankton floats in the environment where both food and bacteria that can provide help in digesting such food are available. In addition, there is probably redundancy for beneficial bacterial functions in the environment, not allowing a strict host‐microbiome association to originate and persist.

中文翻译：

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淡水浮游动物微生物组的组成高度灵活，并受到环境的强烈影响

众所周知，与植物和动物中的微生物结合对宿主的存活和健康有益，但是微生物组作用的普遍性仍在争论中。对于某些动物，微生物组组成的相似性反映了宿主的分类学相关性，这种模式被称为系统共生。模式背后的机制可能是由于共同进化和/或相关的生态约束。现有的知识在很大程度上受模型物种的微生物群落支配，这一事实阻碍了一般性结论。在这里，我们通过分析淡水浮游动物不同物种（包括轮虫，枝角类和co足类）的微生物群落的物种特异性，耦合田间调查和实验操作，解决了共生共生问题。我们发现没有共生信号，而且每个物种内稳定且一致的“核心”微生物分类群的比例非常低。在实验室实验环境下食物和温度的变化表明，淡水浮游动物的微生物组具有很高的柔韧性，并可能受到外部环境的影响。因此，在整个全息概念中，共进化，严格结合以及与微生物的相互作用对于脊椎动物，珊瑚，海绵和其他动物的作用似乎并不能为所有动物（至少不是淡水浮游动物）所支持。浮游动物漂浮在可提供食物和细菌帮助消化食物的环境中。此外，环境中有益细菌的功能可能存在冗余，