Data from: Similar levels of trophic and functional diversity within damselfish assemblages across Indo–Pacific coral reefs

1. Understanding the forces that influence the dynamics of communities is a key challenge to undertake in changing environments. Despite recent advances in coral reef community ecology, a more comprehensive knowledge about processes (niche related–traits and phylogenies) driving the composition of reef fish community is needed.
2. Here, we conducted a quantitative comparison of these processes in damselfish assemblages that belong to three distinct Indo–Pacific coral reefs differing in taxonomic composition, morphology and degree of human disturbance.
3. We compiled a dataset of eight categorical variables to estimate functional diversity of damselfish assemblages and a second one of stable isotope ratios to evaluate isotopic diversity, a proxy of trophic diversity. Both datasets represent the eco–functional diversity and provide insight into niche–related traits. Indices were then computed to grasp complementary facets of this diversity: the size of multidimensional space (richness), the partitioning of niches (divergence) and the regularity in the distribution of niches (evenness) within each space. We also tested whether functional and trophic traits displayed some evolutionary niche conservatism.

4. We found that functional richness was influenced by the number of species and functional entities (FEs, unique combination of trait values), while functional spaces mainly overlapped. Functional divergence and evenness indices were similarly high. For trophic diversity, the isotopic richness remained equivalent, while the two other indices were of high values and did not significantly differ. Both functional and trophic traits did not display any phylogenetic conservatism.

5. We demonstrated consistent levels of eco–functional diversity in Indo–Pacific coral reef damselfishes. Each assemblage hosted species whose niches were highly differentiated and evenly distributed in eco-functional spaces of similar sizes, albeit the size of functional space varied with the species richness. Assemblages also tended to share similar functional attributes. The inconsistent phylogenetic structures of eco–functional traits and the similarity in diversity indices suggest that the assemblage composition of damselfishes is mainly driven by niche-related processes rather than by phylogenetic relatedness. Our work helps to determine which mechanisms shape coral reef fish biodiversity and more particularly assemblages issued from replicated events of ecological radiation.

1. 在不断变化的环境中，解析影响群落动态的驱动因子是一项核心研究挑战。尽管珊瑚礁群落生态学近年来取得了诸多进展，但目前仍需更为全面地认知驱动礁鱼群落组成的各类过程——即与生态位相关的性状与系统发育过程。
2. 本研究针对三个分类组成、形态特征及人类干扰程度均存在差异的印度-太平洋珊瑚礁雀鲷群落，开展了上述过程的定量对比分析。
3. 我们构建了包含8个分类变量的数据集，用于估算雀鲷群落的功能多样性；同时构建了另一套基于稳定同位素比值（stable isotope ratios）的数据集，用以评估同位素多样性——后者可作为营养多样性（trophic diversity）的替代指标。两套数据集均表征了生态功能多样性，并可用于解析与生态位相关的性状。随后我们计算了多个指数，以捕捉该多样性的互补维度：多维空间的规模（丰富度，richness）、生态位的分化程度（分歧度，divergence），以及各空间内生态位分布的规律性（均匀度，evenness）。此外，我们还检验了功能性状与营养性状是否存在进化生态位保守性（evolutionary niche conservatism）。
4. 研究结果显示，功能丰富度受物种数量与功能单元（FEs，即性状值的唯一组合）的影响，而各功能空间整体呈现显著重叠。功能分歧度与均匀度指数均处于较高水平。就营养多样性而言，同位素丰富度维持在相近水平，其余两项指数数值同样较高且无显著差异。功能性状与营养性状均未表现出任何系统发育保守性。
5. 本研究证实，印度-太平洋珊瑚礁雀鲷的生态功能多样性水平具有一致性。尽管功能空间的规模随物种丰富度变化而有所差异，但每个群落中的物种均具有高度分化的生态位，且在规模相近的生态功能空间中均匀分布。各群落也倾向于拥有相似的功能属性。生态功能性状的系统发育结构不一致，加之多样性指数的相似性，表明雀鲷群落的组成主要由与生态位相关的过程驱动，而非系统发育亲缘关系。本研究有助于阐明塑造珊瑚礁鱼类生物多样性的核心机制，尤其是由重复生态辐射事件所形成的群落的构建机制。