浮游类纤毛虫作为海洋微型食物网的主要组成部分在海洋生态系统物质循环和能量流动中发挥着重要作用。关于该类生物的多样性研究，全球范围内一直没有大规模展开，导致该类生物的生态学研究远远落后于其它海洋微型浮游生物，其在全球各海域生态系统中功能与地位无从谈起，其地理分布格局仍未知。基于以上原因，本项目拟通过中-奥双方的优势合作，对西北太平洋和北大西洋浮游类纤毛虫的多样性与进化关系开展大规模研究。结合双方在分类学、细胞学、分子生物学、生物信息学等多学科的技术优势，全面研究浮游类纤毛虫的形态特征、超微结构、细胞发生、基因条形码及环境样品DNA测序信息，最终基于大数据，探讨其在大尺度范围内多样性分布特征及系统进化关系，揭示其全球地理分布格局。从而为廓清该类生物在海洋环境中的生态地位提供重要的基础资料，为全球海洋生态系统动态变化机制探讨、环境保护、生物资源可持续利用等提供理论依据。

Ciliated protozoa are unicellular eukaryotes. The Oligotrichea is a characteristic group of marine pelagial ciliates and an essential component of the microbial loop. They comprise ~ 1,200 species, which probably represent only < 20% of the real biodiversity. Due to the difficulties of identification, biodiversity of Oligotrichea ciliates in worldwide sea are not well known. This restricted knowledge affects phylogenetic inferences as well as estimates of ecosystem functioning and biogeographical distribution; accordingly, it is still unknown whether these planktonic species are dispersal limited or cosmopolitan. Therefore, an investigation on the biodiversity and evolutionary relationships of ciliates from Northwest Pacific Biodiversity Hotspot and the North Atlantic will be carried out..The main proposal objectives are (i) descriptions of Oligotrichea from the China Seas at highest scien¬tific level including barcoding and cell division, (ii) ultrastructural studies in the northwest Pacific endemites and taxa relevant for the proof of evolutionary hypotheses, (iii) performing cladistic and phylogenetic analyses, and (iv) comparing the biodiversity of Oligotrichea in different oceans and testing the hypothesis of dispersal limitation in planktonic ciliates from the China Seas, using high-throughput sequencing and sequence similarity networks. Only by means of the Chinese/Austrian collaboration, the project aims can be reached, especially owing to the provision of material by the Chinese group and additional samples for the biogeographical investigations from the North Sea and Mediterranean provided by the Austrian group as well as the combination of ultrastructural investigations and cladistic analyses (by Austrian group) with barcoding and phylogenetic inferences (by Chinese group). .Based on big data from the northwest Pacific biodiversity hotspot and the north Atlantic, this first joint ciliate project between Austria and China will clarify the specific composition of planktonic ciliates in this area and provide important insights into evolutionary relationships as well as their biogeographical distribution, which will hopefully provide scientific basis for further understanding the biological resources and ecological processes in the worldwide sea.