中文摘要：

生态位与种间竞争、资源利用密切联系,体现了物种在群落中利用资源的能力.为探明三门湾浮游动物分布格局的形成和影响因素,分别采用Shannon公式和Petrailis指数测定了浮游动物优势种生态位宽度和生态位重叠,并通过典范对应分析研究生态位分化状况.结果表明：百陶带箭虫、背针胸刺水蚤、短尾类幼虫等沿岸种的空间生态位较宽,而肥胖软箭虫、中华假磷虾等外海种的空间生态位较窄;具有捕食-被捕食关系的不同类群物种（如箭虫、仔鱼和水母分别与桡足类）有较高的生态位重叠,而同一类群物种（如桡足类及箭虫）间的生态位重叠值较低;浮游动物分布受温度、盐度和叶绿素a的影响较大,受营养盐影响较小.浮游动物空间生态位与生活类型、种间竞争、摄食等多种因素相关.

英文摘要：

Ecological niche has close relations with inter-species competition and resources utiliza- tion, and thus, can be used as an indicator to symbolize the resources utilization capability of cer- tain groups of related species. In this paper, the niche breadth and overlap of the dominant zoo- plankton species in the Sanmen Bay of Zhejiang were determined by Shannon＇s formula and Petraitis index, respectively, and the differentiation of the niche was studied by canonical correspondence analysis （CCA）, aiming to approach the distribution features of coastal zooplankton and related af- fecting factors in the Bay. In the study area, some coastal species such as Zonosagitta bedoti, Cen- tropages dorsispinatus, and brachyuran larvae had wider niche breadth than the pelagic species such as Flaccisagitta enflata and Pseudeuphausia sinica, and the species of different groups with prey- predator relation had a greater niche overlap than those of the same groups without this relation. The CCA analysis showed that the spatial distribution of the zooplankton was more affected by water tem- perature, salinity, and chlorophyll a content rather than nutrients. The spatial niche of the zoo- plankton species was correlated with their living habit, inter-species competition, and prey- preda- tor relationship.