中文摘要：

海南省是我国典型的热带区域，目前对该地区浮游动物的研究和报道极少．为了解该地区轮虫的群落组成，于2006年12月和2007年5月对分布于海南省7座典型的水库敞水区进行了采样调查．共采集到轮虫32种，多为营浮游性生活的广温性和嗜温性种类．在不同时期，水库具体优势种类及其相对优势度有一定差别，主要优势种个体较小且有被甲．在丰水期，剪形臂尾轮虫和镰状臂尾轮虫为主要优势种，在枯水期则以柬隐三肢轮虫为主要优势种．海南省7座水库的平均丰度和生物量分别为66．8ind．／L和21．6μg／L，均远低于亚热带和温带地区．总体上，海南省水库敞水区轮虫呈现出种类少、个体小、丰度低的特点．尽管两次采样期间的轮虫优势种的相对丰度存在一定变化，但轮虫的种类组成结构相对一致，反映出该地区水库轮虫的群落结构具有较高稳定性．

英文摘要：

Hainan Province is at a tropical zone in South China. Zooplankton diversity there has rarely been investigated. In order to collect basic data and understand the community structure of rotifers in Hainan Province, seven typical reservoirs were sampled in December of 2006 and May of 2007. 32 species were identified, among which the majority was eurythermal or mesophilie species. In the two sampling periods, the dominant species and their relative dominance in abundance varied between different reservoirs, almost all the dominant species were small sized ones with armor. The dominant species were Brachionusforficula and Brachionus falcatus in the early flood season and Filinia camasecla in the late dry season. The average abundance and biomass of rotifers were 66.8ind./L and 21.6μg/L, respectively, which both were lower than those in the subtropics and temperate zones. In general, the rotifers were characterized by low species diversity, small body size and low abundance. Although the relative abundance of the dominant rotifers varied slightly between the dry and flood seasons, the consistent species composition indicates that the rotifers keep a steadily community structure in the tropical reservoirs.