ABSTRACT

Calcified macroalgae play an important role in the settlement and metamorphosis of invertebrate larvae in coral reef ecosystems. However, little is known about the algal-associated bacterial communities and their effects on larval settlement. In this study, the responses of larvae of the coral Pocillopora damicornis to calcified algae (Porolithon onkodes, Halimeda cylindracea, Halimeda opuntia and Amphiroa fragilissima) were evaluated. The results revealed that Por. onkodes and H. cylindracea significantly enhanced the rates of settlement and metamorphosis, whereas fewer larvae settled on Am. fragilissima and H. opuntia. Amplicon pyrosequencing of the V3–V4 region of 16S rDNA was applied to investigate the relationship between algal bacterial community and larval settlement. Principal coordinates analysis demonstrated that the bacterial community composition of H. opuntia was more similar to that of Am. fragilissima, but clearly distinct from those of H. cylindracea and Por. onkodes. Furthermore, the relative abundances of bacteria were highly diverse among different algae. H. opuntia had higher percentages of Thalassobius, Pelagibius and SM1A02, whereas the abundances of Mycoplasma and Suttonella were significantly higher in H. cylindracea than other algae. Our results showed that larval settlement/metamorphosis was strongly correlated with the bacterial community composition and with the relative abundance of a few operational taxonomic units.

中文翻译：

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钙化大型藻类及其细菌群落与造礁珊瑚Pocillopora damicornis的幼体沉降和变态有关

摘要

钙化大型藻类在珊瑚礁生态系统中的无脊椎动物幼体的沉降和变态中起重要作用。但是，关于藻类相关细菌群落及其对幼虫沉降的影响知之甚少。在这项研究中，评估了珊瑚Po虫幼虫对钙化藻类（Porolithon onkodes，Halimeda cylindracea，Halimeda opuntia和Amphiroa fragilissima）的反应。结果显示Por。onkodes和H. cylindracea显着提高了定居和变态的速度，而在Am上定居的幼虫较少。脆弱和H.仙人掌。应用16S rDNA V3-V4区域的扩增子焦磷酸测序来研究藻类细菌群落与幼虫沉降之间的关系。主坐标分析表明，H。opuntia的细菌群落组成与Am。相似。fragilissima，但明显不同于H. cylindracea和Por。Onkodes。此外，不同藻类中细菌的相对丰度差异很大。H. opuntia的Thalassobius，Pelagibius和SM1A02的百分比较高，而支原体和Suttonella均显著高于H. cylindracea的比其他藻类。我们的结果表明，幼虫的沉降/变态与细菌群落组成以及一些操作分类单元的相对丰度密切相关。