The Atlantic‐Mediterranean polychaete Sabellaria alveolata lives in agglutinated tubes adjoined to each other to form discrete reef‐like bioconstructions in shallow‐water settings characterised by high hydrodynamic energy where sediment particles are constantly resuspended. Tubes are built with sand grains glued by proteinaceous secretions. Analyses of a reef fragment collected near Sampieri (SE Sicily, Sicily Strait) allowed the first detailed description of the tube architecture and biocement of this worms from the Mediterranean. The tube consists of an inner thin organic membrane and three agglutinated layers including: (a) a thin inner layer of flat grains arranged side by side; (b) a thick mid layer with a frame of relatively large sub‐rounded grains with cavities partly filled by small grains; and (c) a thin outer layer of large, flat to curved, usually biogenic clasts diverging towards the opening. This particular architecture is distinctive of the family. Morphological and epifluorescence observations revealed that biocement consists of drops at the contact between sub‐spherical grains and strips along edges of flat grains. Biocement is a solid foam‐like material characterised by high abundance of carbon; the presence of phosphorous and nitrogen confirms its proteinaceous composition. Due to the electrostatic interaction with the proteins, calcium and magnesium are most likely complexed to the cement rather than being trapped in the cells. These elements contribute to the solidification of the glue and stabilisation of the tube structure. However, the organic nature of cement and the high energy of their habitat, make sabellariid reefs dynamic and ephemeral, and the preservation as fossils unlikely, with a confident record only extending back to the Miocene.

中文翻译：

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来自地中海的 Sabellaria alveolata 沙堡蠕虫：对管结构和生物水泥的新见解

大西洋-地中海多毛类 Sabellaria alveolata 生活在彼此相邻的凝集管中，在浅水环境中形成离散的礁状生物结构，其特征是沉积物颗粒不断重新悬浮的高流体动力能量。管子由由蛋白质分泌物粘合的沙粒构成。对在 Sampieri（西西里岛东南部，西西里海峡）附近收集的珊瑚礁碎片进行分析，首次详细描述了这种来自地中海的蠕虫的管结构和生物水泥。该管由内部薄有机膜和三个粘合层组成，包括： (a) 并排排列的扁平颗粒的薄内层；(b) 厚的中间层，具有较大的亚圆形颗粒框架，其中部分由小颗粒填充；(c) 一个大的薄外层，扁平到弯曲，通常是生物碎屑向开口发散。这种特殊的建筑是这个家族的独特之处。形态学和落射荧光观察表明，生物水泥由亚球形颗粒和沿扁平颗粒边缘的条带之间接触处的液滴组成。生物水泥是一种固体泡沫状材料，其特点是碳含量高；磷和氮的存在证实了其蛋白质成分。由于与蛋白质的静电相互作用，钙和镁最有可能与水泥复合而不是被困在细胞中。这些元素有助于胶水的固化和管结构的稳定。然而，水泥的有机性质和它们栖息地的高能量，使 sabellariid 珊瑚礁充满活力和短暂，