水生态学杂志

原生动物对环境变化反应敏锐，是水生态系统微生物食物网、物质循环和能量流动中的重要结构和功能组成部分。青海湖作为我国最大的内陆咸水湖，是维系青藏高原生态安全的重要水体，是世界高原内陆湖泊湿地类型的典型代表。为了探究青海湖流域原生动物群落结构及其与环境因子之间的关系，于2020年8月对青海湖流域的入湖河流、湖滨带、主湖区及子湖共32个样点进行水环境样品采集，共获得水体样品95份，利用宏基因组测序技术和生物信息学方法从分子水平开展了该流域原生动物多样性和群落结构及其影响因素研究。主要结果如下：（1）共注释到176个原生动物分类单元（Operational Taxonomic Units,OTU），隶属于12门19纲43目61科72属；（2）青海湖流域原生动物多样性为入湖河流>湖滨带>子湖>主湖区，且4类水体环境原生动物群落结构存在显著差异；（3）原生动物群落受水体酸碱度、盐度、水温、溶解性总固体、浊度、总氮、总磷等环境因子的影响；（4）原生动物与其他浮游生物共现网络从入湖河流、湖滨带、子湖到主湖区，模块性逐渐变低，生物类群间的互作网络逐渐碎片化。青海湖流域原生动物的调查结果可为将来该流域的水生态环境健康评估提供依据。

Protozoa are a group of single-celled eukaryotes with a wide variety of species, broad distribution, short life cycle and a keen response to environmental changes. They are an important structural and functional component of the microbial food web, and the material circulation and energy flow in aquatic ecosystems. As the largest inland saltwater lake in China, Qinghai Lake is a representative of plateau inland lakes and an important water body that is crucial for maintaining the ecological stability of the Qinghai-Tibet Plateau. In this study, we explored the community structure, species diversity and the factors influencing protozoa in four waters of the Qinghai Lake basin(inflow river, near shore, open water and sublake) using metagenomic sequencing and bioinformatics. In August 2020, water samples were collected at32 sampling sites in the four waters for the determination of water environmental parameters and for metagenomic sequencing. Results are as follows:(1) A total of 176 protozoan operational taxonomic units(OTUs) were identified, belonging to 72 genera, 61 families, 43 orders, 19 classes and 12 phyla.(2) Protozoan diversity in the Qinghai Lake basin presented significant spatial differences, and the diversity of the four waters was in the order of inflow river>near shore>sub-lake>open water.(3) The protozoan community was affected by pH, salinity, water temperature, total dissolved solids, turbidity, total nitrogen, and total phosphorus.(4) The co-occurring protozoan networks and other plankton in the inflow river, near shore, sub-lake and open waters gradually became less modular, and the interaction networks among taxonomic groups gradually became fragmented. In summary, high-throughput sequencing was used to conduct a comprehensive investigation of the protozoa in the Qinghai Lake basin, and the results provide a basis for assessing and monitoring the aquatic ecosystems of Qinghai Lake basin.