Changes in invertebrate body size‐distributions that follow loss of habitat‐forming species can potentially affect a range of ecological processes, including predation and competition. In the marine environment, small crustaceans and other mobile invertebrates (‘epifauna') represent a basal component in reef food webs, with a pivotal secondary production role that is strongly influenced by their body size‐distribution. Ongoing degradation of reef habitats that affect invertebrate size‐distributions, particularly transformation of coral and kelp habitat to algal turf, may thus fundamentally affect secondary production. Here we explored variation in size spectra of shallow epifaunal assemblages (i.e. the slope and intercept of the linear relationship between log abundance and body size at the assemblage level) across 21 reef microhabitats distributed along an extensive eastern Australian climatic gradient from the tropical northern Great Barrier Reef to cool temperate Tasmania. When aggregated across microhabitats at the site scale, invertebrate body size spectra (0.125–8 mm range) were consistently log‐linear (R² ranging 0.87–0.98). Size spectra differed between, but not within, major groups of microhabitats, and exhibited little variability between tropical and temperate biomes. Nevertheless, size spectra showed significant tropical/temperate differences in slopes for epifauna sampled on macroalgal habitats, and in elevation for soft coral and sponge habitats. Our results reveal epifaunal size spectra to be a highly predictable macro‐ecological feature. Given that variation in epifaunal size spectra among groups of microhabitats was greater than variation between tropical and temperate biomes, we postulate that ocean warming will not greatly alter epifaunal size spectra directly. However, transformation of tropical coral and temperate macroalgal habitats to algal turfs due to warming will alter reef food web dynamics through redistribution of the size of prey available to fishes.

中文翻译：

---

小型无脊椎动物消费者在珊瑚礁栖息地和气候带上产生一致的尺寸谱

随着失去栖息地的物种的消失，无脊椎动物体型的分布变化可能会影响一系列生态过程，包括捕食和竞争。在海洋环境中，小型甲壳类动物和其他无脊椎动物（“ epifauna”）是礁石食物网中的基础成分，其次要生产作用受到其体型分布的强烈影响。因此，影响无脊椎动物大小分布的珊瑚礁栖息地的持续退化，尤其是将珊瑚和海带栖息地转变为藻类的土地，可能从根本上影响次级生产。在这里，我们探讨了浅表生动物群（即 分布在21个礁石微生境上的对数丰度与体型大小之间线性关系的斜率和截距，分布在从热带北部大堡礁到塔斯马尼亚凉爽的澳大利亚东部广泛的气候梯度上。当在场所规模上跨微生境聚集时，无脊椎动物体谱（0.125–8 mm范围）始终呈对数线性（R²范围为0.87–0.98）。大小谱在主要的微生境组之间有所不同，但在内部却没有，并且在热带和温带生物群落之间几乎没有变化。然而，尺寸谱显示在大型藻类生境中采样的动物群落的坡度以及在软珊瑚和海绵生境中的海拔的热带/温带差异显着。我们的结果表明，表观粪便大小谱是高度可预测的宏观生态学特征。鉴于微生境组之间的表观规模谱的变化大于热带和温带生物群落之间的变化，我们推测海洋变暖不会直接极大地改变表观规模谱。然而，