The identification of the mechanisms underlying patterns of species co‐occurrence is a way to identify which process(es) (niche, neutral, or both) structure metacommunities. The current paper had the goal of identifying patterns of co‐occurrence in Neotropical stream fish and determining which processes structure the fish metacommunity, and identifying any gradients underlying this structure. Results indicated that the metacommunity formed by the species pool was structured by a pattern of nested co‐occurrence (hyperdispersed species loss) and a mass‐effect mechanism. However, a set of core species, displaying a Clementsian pattern, was structured by a species‐sorting mechanism. Both, hyperdispersed species loss and the Clementsian patterns point to a discrete set of communities within the metacommunity. These communities could be isolated by the water physicochemical conditions or morphological characteristics of the stream channel.

中文翻译：

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新热带淡水鱼类鱼类群落结构的元素

对物种共生模式潜在机制的识别是一种识别哪些过程（利基，中性或两者兼有）构成元社区的方法。本论文的目的是确定新热带河鱼类的共生模式，确定哪种过程构成了鱼类的亚群落，并确定了这种结构背后的任何梯度。结果表明，物种库形成的元社区是由嵌套共生（物种过度分散）模式和质量效应机制构成的。但是，一组展示了克莱门特模式的核心物种是由物种分类机制构成的。高度分散的物种流失和克莱门茨模式都指向元社区内的离散社区。