Department of Biological, Geological, and Environmental Sciences, University of Catania, Catania, Italy.
Department of Biology, Ecology, and Earth Sciences, University of Calabria, Cosenza, Italy.
J Morphol. 2022 Oct;283(10):1350-1358. doi: 10.1002/jmor.21507. Epub 2022 Sep 9.
The Atlantic-Mediterranean polychaete Sabellaria spinulosa (Leuckart, 1849) lives in agglutinated tubes forming discrete reef-like bioconstructions on shallow-water bottoms beaten by waves where sediment particles are constantly resuspended. Tubes are built with sand grains glued by a proteinaceous cement. Analyses of a S. spinulosa reef sample of this worm collected off the Casarza coast (central Adriatic Sea) allowed the description of its tube architecture and gluing modality. The tube consists of three layers of agglutinated sand: (a) a thin inner layer with sandy particles arranged side by side with a flat side facing the tube lumen (b) a thick middle layer with larger isodiametric and squat grains with empty pores in between; and (c) a thin discontinuous outer layer of heterometric clasts, prevalently large and flat, diverging towards the opening. This fits the general tube construction known for S. alveolata and in general for tubes of the sabellariidae family, but compared to Sabellaria alveolata, S. spinulosa possesses a smaller tube with a wall about 1/3 thick; the agglutinated sandy elements are finer, and some number of muddy particles participates in the tube construction. Morphological and epifluorescence observations revealed that biocement portions are irregularly and haphazardly distributed compared with those of S. alveolata that consist of drops and strips of glue carefully placed. Adjacent tubes leave empty interspaces in between them only locally filled by loose sand, extremely reduced to absent in S. alveolata.
大西洋-地中海多毛类沙蚕 Sabellaria spinulosa（Leuckart，1849）生活在由黏合管组成的离散状珊瑚状生物构造中，这些构造位于浅水底，海浪不断冲击，沉积物颗粒不断悬浮。管由黏合沙粒的蛋白质胶组成。对从卡萨尔扎海岸（亚得里亚海中部）采集的这种沙蚕的 S. spinulosa 珊瑚礁样本进行分析，描述了其管结构和黏合方式。管由三层黏合沙组成：（a）薄的内层，沙粒并排排列，朝向管腔的一侧为平面；（b）厚的中间层，有较大的等径和矮胖的颗粒，颗粒之间有空隙；（c）薄的不连续外层，有不同大小的碎屑，主要是大而平坦的，向开口处发散。这与已知的 S. alveolata 以及一般的沙蚕科管的总体结构相吻合，但与 S. alveolata 相比，S. spinulosa 的管较小，壁约为 1/3 厚；黏合的沙粒元素更细，一些泥质颗粒也参与了管的构建。形态学和荧光观察表明，与 S. alveolata 不同，生物胶部分分布不规则且杂乱无章，S. alveolata 的胶由精心放置的胶滴和胶条组成。相邻的管之间仅在局部有空隙，由松散的沙子填充，而在 S. alveolata 中则空隙极小或不存在。
