Gastrotricha and Platyhelminthes form a clade called Rouphozoa. Representatives of both taxa are main components of meiofaunal communities, but their role in the trophic ecology of marine and freshwater communities is not sufficiently studied. Traditional collection methods for meiofauna are optimized for Ecdysozoa, and include the use of fixatives or flotation techniques that are unsuitable for the preservation and identification of soft-bodied meiofauna. As a result, rouphozoans are usually underestimated in conventional biodiversity surveys and ecological studies. Here, we give an updated outline of their diversity and taxonomy, with some phylogenetic considerations. We describe successfully tested techniques for their recovery and study, and emphasize current knowledge on the ecology, distribution, and dispersal of freshwater gastrotrichs and microturbellarians. We also discuss the opportunities and pitfalls of (meta)barcoding studies as a means of overcoming the taxonomic impediment. Finally, we discuss the importance of rouphozoans in aquatic ecosystems and provide future research directions to fill in crucial gaps in the biology of these organisms needed for understanding their basic role in the ecology of benthos and their place in the trophic networks linking micro-, meio-, and macrofauna of freshwater ecosystems.

中文翻译：

---

好奇且被忽视的软体小型动物：Rouphozoa（腹毛类和扁形动物）


腹毛纲和扁形动物形成一个分支，称为 Rouphozoa。这两个类群的代表都是小型动物群落的主要组成部分，但它们在海洋和淡水群落营养生态中的作用尚未得到充分研究。小型动物的传统收集方法针对蜕皮动物进行了优化，包括使用不适合保存和鉴定软体小型动物的固定剂或浮选技术。因此，在传统的生物多样性调查和生态研究中，红体动物通常被低估。在这里，我们给出了它们的多样性和分类学的最新概述，并考虑了一些系统发育的因素。我们描述了经过成功测试的恢复和研究技术，并强调了淡水腹毛虫和微涡虫的生态、分布和扩散方面的最新知识。我们还讨论了（元）条形码研究作为克服分类学障碍的一种手段的机遇和陷阱。最后，我们讨论了红体动物在水生生态系统中的重要性，并提供了未来的研究方向，以填补这些生物体生物学中的关键空白，以了解它们在底栖动物生态中的基本作用以及它们在连接微、小型生物的营养网络中的地位。 - 以及淡水生态系统的大型动物群。