Ultrastructural and elemental characterization of the extracorporeal tube of the sessile rotifer Floscularia conifera (Rotifera: Gnesiotrocha)
Ultrastructural and elemental characterization of the extracorporeal tube of the sessile rotifer Floscularia conifera (Rotifera: Gnesiotrocha)
复制标题
固着轮虫 Floscularia conifera（轮虫纲：Gnesiotrocha）体外管的超微结构和元素表征
DOI：
10.1111/ivb.12230
复制
发表时间：
2018
影响因子：
1.2
通讯作者：
Hochberg, Rick
中科院分区：
文献类型：
--
作者：
Yang, Hui;Hochberg, Rick
轮虫是水生微型无脊椎动物，生活在浮游生物或底栖动物中，其中可能包括各种大型植物。在这些周围生长形式的轮虫中，有些轮虫已经采取了无根的存在方式，并在身体周围分泌保护管。一种常见的管，由小圆球组成。到目前为止，人们已经知道了黄花花的建造过程和一些精细的结构细节，但关于管的组成和超微结构的许多问题仍然没有答案。在这里，我们分别使用透射电子显微镜和扫描电子显微镜-能量色散X射线能谱（SEM-EDS）研究了被认为是姐妹种的针叶花（Floscularia conifera）颗粒的超微结构和元素组成。我们发现了一些新的细节，增加了关于植物管形成生理的重要信息。首先，我们注意到内部分泌膜很薄，电子发光，并支持外部微球。颗粒的大小相对一致，并且在其内表面有一个小凹陷。所有颗粒都单独包裹在一个分泌膜中，该膜完全封装了从周围水中收集的悬浮物质。颗粒的元素特征显示它们主要由碳(C)、氮(N)和氧(O)组成，还有一些硅（Si）含量，可能是硅藻壳的结果。其他微量元素，如铁（Fe）和钠（Na）也存在，可能是合并细菌和悬浮物质的结果。轮虫幼虫在过滤池水中培养时，颗粒主要由碳和氧组成，氮含量很少，不含硅；铁以较小的量存在。这些新发现有助于更好地理解轮虫管结构和管组成的生理学，以及它们未来在理解淡水环境变化是否以及如何影响这些因素方面的应用。
Rotifers are aquatic microinvertebrates that live in the plankton or in the benthos, which may include a variety of macrophytes. Among these periphytic forms of rotifers, some have taken up a sessile existence and secrete protective tubes around their bodies. One type of tube common to species ofFlosculariais made of small round pellets. To date, the building process and some fine structural details are known forFloscularia ringens, but many questions about the composition of the tube and its ultrastructure still remain unanswered. Here, we use transmission electron microscopy and scanning electron microscopy–energy dispersive X‐ray spectroscopy (SEM–EDS) to study the ultrastructure of the pellets and their elemental composition, respectively, in the putative sister species,Floscularia conifera. We revealed several new details that add important information about the physiology of tube‐making in species ofFloscularia. First, we note an inner secretory membrane that is thin, electron lucent, and supports the external pellets. The pellets are relatively consistent in size and have a small depression on their inner surface. All pellets are individually wrapped in a secretory membrane that completely encapsulates suspended materials collected from the surrounding water. Elemental signatures of pellets reveal they consist mostly of carbon (C), nitrogen (N), and oxygen (O), with some silicon (Si) content that is likely the result of diatom shells. Other trace elements such as iron (Fe) and sodium (Na) are also present and likely the result of incorporated bacteria and suspended materials. When larval rotifers are cultured in filtered pond water, the pellets consist mostly of C and O, with little N and no Si; Fe is present in smaller amounts. These new discoveries provide a better understanding of the physiology of rotifer tube construction and tube composition, and their future utility in understanding if and how changes in freshwater environments might impact these factors.