珠江广州河段轮虫群落结构的初步研究

PRIMARY STUDY ON ROTIFER COMMUNITY STRUCTURE IN THE GUANGZHOU SEGMENT OF THE RIVER PEARL

2004年4月—2005年4月,对珠江广州河段轮虫群落结构特征进行了初步研究。经鉴定,共发现轮虫65种(包括亚种),其中西氏三肢轮虫(Filinia novaezealandiae)、华美腔轮虫(Lecane elegans)为我国的新记录种。优势种为裂痕龟纹轮虫(Anuraeopsis fissa)、角突臂尾轮虫(Brachionus angularis)、尾突臂尾轮虫(Brachionus caudatus)、Filinia no-vaezealandiae、暗小异尾轮虫(Trichocerca pusilla)和微型多突轮虫(Liliferotrocha subtilis)。调查发现径流量对轮虫密度有重要影响,轮虫的两次密度高峰分别出现在春末夏初和秋季。丰水期,轮虫密度较低;枯水期前期,轮虫密度较高;枯水期后期,轮虫密度较低。此外,轮虫种群还受到温度、盐度等因素的影响。研究结果表明轮虫在河流生态系统中具有重要作用。

The spatial and temporal distribution of planktonic rotifers in the Guangzhou segment of the River Pearl, China, was investigated at half of month intervals from April 2004 to April 2005. Samples were taken at two fixed sites （Zhongda port and Huangpu harbour） . 65 species of rotifer belonging to 20 genera and 13 families were identified during the survey period. Filinia novaezealandiae and Lecane elegans were confirmed as new records in China. The dominant species were Anuraeopsisfissa, Brachionus angularis , Brachionus caudatus , Filinia novaezealandiae , Trichocerca pusilla and Liliferotrocha subtilis . Results indicated that river discharge had important effect on the density fluctuation of rotifers. The highest densities were recorded in the beginning of summer and the end of autumn. The lowest densities were in the rainy season （flood period） and the late dry season （low water period）, respectively. The importance of salinity and temperature in determining rotifer community structure and seasonal succession are analyzed. Results indicated that rotifers played an important role in river ecosystems.