Data_Sheet_4_Sponges and Their Microbiomes Show Similar Community Metrics Across Impacted and Well-Preserved Reefs.PDF

Sponge diversity has been reported to decrease from well-preserved to polluted environments, but whether diversity and intra-species variation of their associated microbiomes also change as function of environmental quality remains unknown. Our study aimed to assess whether microbiome composition and structure are related to the proliferation of some sponges and not others under degraded conditions. We characterized the most frequent sponges and their associated bacteria in two close areas (impacted and well-preserved) of Nha Trang Bay (Indo-Pacific). Sponge assemblages were richer and more diverse in the well-preserved reefs, but more abundant (individuals/m. transect) in the impacted environments, where two species (Clathria reinwardti and Amphimedon paraviridis) dominated. Sponge microbiomes from the polluted zones had, in general, lower bacterial diversity and core size and consequently, higher intra-species dispersion than microbiomes of sponges from the well-preserved environments. Microbial communities reflect the reduction of diversity and richness shown by their host sponges. In this sense, sponges with less complex and more variable microbiomes proliferate under degraded environmental conditions, following the ecological paradigm that negatively correlates community diversity and environmental degradation. Thereby, the diversity and structure of sponge microbiomes might indirectly determine the presence and proliferation of sponge species in certain habitats.

已有研究证实，海绵物种多样性从保存完好的海域到受污染生境中呈下降趋势，但与之共生的微生物组（microbiome）的多样性及种内变异是否随环境质量变化而改变，目前仍未明确。本研究旨在探究：在环境退化条件下，微生物组的组成与结构是否与部分海绵物种的增殖相关，而与其他物种无关。我们对印太海域芽庄湾两处邻近区域（受干扰区域与保存完好区域）内最常见的海绵物种及其共生细菌进行了表征分析。结果显示，保存完好的珊瑚礁区域中，海绵群落的物种丰富度与多样性均更高；而受干扰环境中，海绵个体丰度（单位样带个体数）更为突出，且以Clathria reinwardti与Amphimedon paraviridis两种海绵为绝对优势种。总体而言，相较于来自保存完好环境的海绵，污染区域海绵的微生物组所携带的细菌多样性与核心菌群规模更低，因此其种内群落离散度更高。微生物群落的变化趋势与宿主海绵的多样性及丰富度下降情况相一致。据此，遵循"群落多样性与环境退化呈负相关"的经典生态学范式，在环境退化条件下，拥有较低复杂度且变异程度更高的微生物组的海绵物种更易实现增殖。由此可见，海绵微生物组的多样性与结构或可间接决定特定生境中海绵物种的存续与增殖能力。