Chan Vera Bin San, Vinn Olev, Li Chaoyi, Lu Xingwen, Kudryavtsev Anatoliy B, Schopf J William, Shih Kaimin, Zhang Tong, Thiyagarajan Vengatesen
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region.
Department of Geology, University of Tartu, Ravila 14A, 50411 Tartu, Estonia.
J Struct Biol. 2015 Mar;189(3):230-7. doi: 10.1016/j.jsb.2015.01.004. Epub 2015 Jan 16.
The serpulid tubeworm, Hydroides elegans, is an ecologically and economically important species whose biology has been fairly well studied, especially in the context of larval development and settlement on man-made objects (biofouling). Nevertheless, ontogenetic changes associated with calcareous tube composition and structures have not yet been studied. Here, the ultrastructure and composition of the calcareous tubes built by H. elegans was examined in the three early calcifying juvenile stages and in the adult using XRD, FTIR, ICP-OES, SEM and Raman spectroscopy. Ontogenetic shifts in carbonate mineralogy were observed, for example, juvenile tubes contained more amorphous calcium carbonate and were predominantly aragonitic whereas adult tubes were bimineralic with considerably more calcite. The mineral composition gradually shifted during the tube development as shown by a decrease in Sr/Ca and an increase of Mg/Ca ratios with the tubeworm's age. The inner tube layer contained calcite, whereas the outer layer contained aragonite. Similarly, the tube complexity in terms of ultrastructure was associated with development. The sequential appearance of unoriented ultrastructures followed by oriented ultrastructures may reflect the evolutionary history of serpulid tube biominerals. As aragonitic structures are more susceptible to dissolution under ocean acidification (OA) conditions but are more difficult to be removed by anti-fouling treatments, the early developmental stages of the tubeworms may be vulnerable to OA but act as the important target for biofouling control.
螺旋虫管虫（Hydroides elegans）是一种在生态和经济方面都很重要的物种，其生物学特性已得到相当充分的研究，特别是在幼体发育和在人造物体上附着（生物污损）的背景下。然而，与钙质管的组成和结构相关的个体发育变化尚未得到研究。在此，利用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、电感耦合等离子体发射光谱（ICP - OES）、扫描电子显微镜（SEM）和拉曼光谱，对秀丽盘管虫在三个早期钙化幼体阶段和成虫阶段所构建的钙质管的超微结构和组成进行了研究。观察到了碳酸盐矿物学方面的个体发育变化，例如，幼体管含有更多的无定形碳酸钙，主要为文石质，而成虫管是双矿物的，方解石含量明显更多。随着管虫年龄的增长，管发育过程中矿物组成逐渐变化，表现为Sr/Ca降低和Mg/Ca比值升高。管的内层含有方解石，而外层含有文石。同样，从超微结构来看，管的复杂性与发育有关。无定向超微结构随后是定向超微结构的依次出现可能反映了螺旋虫管生物矿物的进化历史。由于文石结构在海洋酸化（OA）条件下更易溶解，但更难通过防污处理去除，管虫的早期发育阶段可能易受海洋酸化影响，但却是生物污损控制的重要目标。
