Marine sponges are abundant and ecologically important components of coral reefs and have been shown to harbour exceptionally high microbial densities, which can differ substantially among sponge species. However, this dichotomy between high and low microbial abundance (HMA, LMA) sponges is still not fully understood, particularly as concerns the archaeal community. This study aims to fill this gap by analysing (using 454-pyrosequencing of the 16S rRNA gene) how the archaeal community varies among known LMA (Stylissa carteri, and Stylissa massa), known HMA (Hyrtios erectus and Xestospongia testudinaria) and unknown HMA/LMA status sponge species (Ectyoplasia coccinea, Paratetilla bacca and Petrosia aff. spheroida) collected in a remote location in which very few sponge microbial composition studies have been previously performed (Mayotte, Comores archipelago, France) and comparing the results with those reported in four other geographical areas. Based on archaeal community composition, the known LMA sponges formed a distinct cluster together with Paratetilla bacca, Ectyoplasia coccinea and seawater while the known HMA sponge X. testudinaria formed a cluster with Petrosia aff. spheroida. The known HMA sponge H. erectus, in turn, had an intermediate archaeal community between HMA sponges and sediment samples. In addition to the above, we also showed significant compositional congruence between archaeal and bacterial communities sampled from the same sponge individuals. HMA sponges were mainly dominated by members assigned to the genus Nitrosopumilus while LMA sponges were mainly dominated by members assigned to the genus Cenarchaeum. In general, there was no clear difference in richness between HMA and LMA sponges. Evenness, however, was higher in HMA than LMA sponges. Whilst the present study corroborates some of the traits commonly associated with the HMA–LMA dichotomy (higher evenness in Mayotte HMA sponges), this was not consistent across geographical areas showing that more research is needed to fully understand the HMA/LMA dichotomy as concerns Archaea.

海洋海绵是珊瑚礁中丰富且具有重要生态意义的组成部分，并且已被证明具有极高的微生物密度，这在海绵物种之间可能存在很大差异。然而，高和低微生物丰度（HMA，LMA）海绵之间的这种二分法仍未完全理解，特别是在古菌群落方面。本研究旨在通过分析（使用 16S rRNA 基因的 454 焦磷酸测序）古菌群落如何在已知 LMA（Stylissa careri和Stylissa massa）、已知 HMA（Hyrtios直立和Xestospongia testudinaria）和未知 HMA/ LMA 海绵种（Ectyoplasia coccinea , Paratilla bacca和彼得罗西亚aff。spheroida）收集在一个偏远地区，在该地区以前很少进行海绵微生物组成研究（马约特岛，科摩罗群岛，法国），并将结果与​​其他四个地理区域报告的结果进行比较。根据古菌群落组成，已知的 LMA 海绵与Paratetilla bacca、Ectyoplasia coccinea和海水形成了一个明显的集群，而已知的 HMA 海绵X. testudinaria与Petrosia aff形成了一个集群。球体。已知的 HMA 海绵H.挺立人反过来，在 HMA 海绵和沉积物样品之间有一个中间古菌群落。除上述内容外，我们还表明从同一海绵个体采样的古菌和细菌群落之间存在显着的组成一致性。HMA 海绵主要由归入 Nitrosopumilus属的成员主导，而 LMA 海绵主要由归入 Cenarchaeum属的成员主导. 总的来说，HMA 和 LMA 海绵的丰富度没有明显差异。然而，HMA 的均匀度高于 LMA 海绵。虽然本研究证实了一些通常与 HMA-LMA 二分法相关的特征（马约特岛 HMA 海绵的均匀度更高），但这在地理区域之间并不一致，这表明需要更多的研究来充分了解 HMA/LMA 二分法与古细菌的关系.