Plate tectonics, topographic structures, ocean currents, and mass extinction: How did these factors shape the current distribution of meiofaunal holobenthic Kinorhyncha in deep-sea basins of the Arctic, Atlantic, and Southern Ocean?

地球表面约有一半被深海占据，那里存在着几种独特的生物和生态系统。这种独特性可能是由几个历史事件或地理运动造成的，例如板块构造、洋流和大灭绝。虽然小型底栖动物往往表现出比深海底栖大型动物更高的生物量和物种多样性，但对它们的分类学、生物地理学和进化知识几乎没有进行过调查。HERE应用项目是基于15个德国和4个美国深海探险队前往北极、大西洋和南大洋的小型动物样本。该项目的目标是利用小型底栖动物群组Kinorhyncha揭示形成目前深海小型底栖动物群落的机制。这项研究将全面复盖上述海洋，并在工作物种层面确定它们的亲缘关系，从而能够发现它们的地方/区域/海洋特征，并比较盆地内、盆地与邻近浅水之间的动物群。一些材料将用于分子系统发育分析，以探测深海动物群和浅水动物群之间的关系。将进行社区结构分析，以比较区域内/区域间社区的相似性。动物群和系统发育比较的这些结果，以及对该地区历史和地质事件的已知知识，将表明小型底栖动物群落是如何在深海海底发展起来的，以及哪些因素对其产生了影响。该项目的成果将有助于了解深海生物的物种多样性、生物地理特征和进化史。

About half of the earth’s surface is occupied by the deep sea where several unique organisms and ecosystem are present. Such an uniqueness may have been created by several historical events or geographical movement, e.g., plate tectonics, ocean currents, and mass extinction. Although meiofauna often shows higher biomass and species diversity than macrofauna in the deep-sea floor, the taxonomical, biogeographical and evolutional knowledge of them has been scarcely investigated. The here applied project is based on meiofauna samples of 15 German and 4 US American deep-sea expeditions to the Arctic, Atlantic, and Southern Ocean. The goal of this project is to reveal the mechanisms which created the current deep-sea meiofaunal community by using the meiofaunal group Kinorhyncha. The study will comprehensively cover the above mentioned oceans and identify the kinorhynchs from there at working species level enabling to detect the local/regional/oceanic characteristics of them and to compare the faunae within basins and between basins and adjacent shallow waters. Some materials will be used for molecular phylogenetic analyses in order to detect the relationships among/between deep-sea faunae and shallow water ones. Community structural analyses will be conducted to compare the (dis)similarities of communities within/between regions. These results of the faunistic and phylogenetic comparisons together with the already known knowledge of the historical and geological events in the area will indicate how meiofaunal community developed on the deep-sea floor and which factors affected them. The results of the project shall contribute to the knowledge on the species diversity, the biogeographical characters, and the evolutional history of deep-sea organisms.