There is a growing interest in the endolithic microbial biofilms inhabiting skeletons of living corals because of their contribution to coral reef bioerosion and the reputed benefits they provide to live coral hosts. Here, we sought to identify possible correlations between coral interspecific patterns in skeletal morphology and variability in the biomass of, and chlorophyll concentrations within, the endolithic biofilm. We measured five morphological characteristics of five coral species and the biomasses/chlorophyll concentrations of their endolithic microbiome, and we compare interspecific patterns in these variables. We propose that the specific density of a coral’s skeleton and its capacity for capturing and scattering incident light are the main correlates of endolithic microbial biomass. Our data suggest that the correlation between light capture and endolithic biomass is likely influenced by how the green microalgae (obligatory microborers) respond to skeletal variability. These results demonstrate that coral species differ significantly in their endolithic microbial biomass and that their skeletal structure could be used to predict these interspecific differences. Further exploring how and why the endolithic microbiome varies between coral species is vital in defining the role of these microbes on coral reefs, both now and in the future.

中文翻译：

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光捕获、骨骼形态学和珊瑚钻孔内石的生物量

由于它们对珊瑚礁生物侵蚀的贡献以及它们为活珊瑚宿主提供的众所周知的好处，人们对栖息在活珊瑚骨骼中的内石微生物生物膜越来越感兴趣。在这里，我们试图确定骨骼形态的珊瑚种间模式与内石生物膜的生物量和叶绿素浓度的变异性之间可能存在的相关性。我们测量了五种珊瑚物种的五种形态特征及其内石微生物组的生物量/叶绿素浓度，并比较了这些变量的种间模式。我们提出珊瑚骨架的比密度及其捕获和散射入射光的能力是内石微生物生物量的主要相关因素。我们的数据表明，光捕获和石内生物量之间的相关性可能受绿色微藻（强制性微孔虫）对骨骼变异的反应方式的影响。这些结果表明，珊瑚物种在其内石微生物生物量方面存在显着差异，并且它们的骨骼结构可用于预测这些种间差异。进一步探索内石微生物组如何以及为什么在珊瑚物种之间发生变化对于定义这些微生物在现在和未来对珊瑚礁的作用至关重要。这些结果表明，珊瑚物种在其内石微生物生物量方面存在显着差异，并且它们的骨骼结构可用于预测这些种间差异。进一步探索内石微生物组如何以及为什么在珊瑚物种之间发生变化对于定义这些微生物在现在和未来对珊瑚礁的作用至关重要。这些结果表明，珊瑚物种在其内石微生物生物量方面存在显着差异，并且它们的骨骼结构可用于预测这些种间差异。进一步探索内石微生物组如何以及为什么在珊瑚物种之间发生变化对于定义这些微生物在现在和未来对珊瑚礁的作用至关重要。