Autozooids of the cheilostome bryozoan Aquiloniella scabra contain rod-like bacteria in the funicular bodies – the complex swellings of the funicular strands. Each funicular body contains symbionts in the central cavity surrounded by a large, synthetically active internal “sheath-cell” (bacteriocyte) and a group of the flat external cells. The tightly interdigitating lobes of these cells form a capsule well-isolated from the body cavity. Slit-like spaces between bacteria are filled with electron-dense matrix and cytoplasmic processes of various sizes and shapes (often branching) produced by the “sheath-cell”. The cell ultrastructure and complex construction of the funicular bodies as well as multiplication of the bacteria in them suggest metabolic exchange between host and symbiont, involving the nourishment of bacteria. We suggest that the bacteria, in turn, influence the bryozoan mesothelial tissue to form the funicular bodies as capsules for bacterial incubation. We present ultrastructural data, discuss possible variants in the development of the funicular bodies in Bryozoa, and propose the possible role of bacteria in the life of their bryozoan host.

中文翻译：

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海洋群体无脊椎动物（苔藓虫）与其细菌共生体之间营养关系的超微结构证据。


唇口动物苔藓动物Aquiloniella scabra的自体动物在索状体（索状线的复杂肿胀）中含有杆状细菌。每个索状体的中央空腔中都包含共生体，共生体被一个大型的、具有合成活性的内部“鞘细胞”（细菌细胞）和一组扁平的外部细胞包围。这些细胞紧密交错的叶形成一个与体腔良好隔离的胶囊。细菌之间的狭缝状空间充满了“鞘细胞”产生的各种大小和形状（通常是分支）的电子致密基质和细胞质过程。索状体的细胞超微结构和复杂结构以及其中细菌的繁殖表明宿主和共生体之间存在代谢交换，涉及细菌的营养。我们认为细菌反过来影响苔藓虫间皮组织形成索状体作为细菌孵化的胶囊。我们提供超微结构数据，讨论苔藓虫索状体发育中可能的变异，并提出细菌在苔藓虫宿主生命中的可能作用。