秋季南沙群岛海域浮游纤毛虫群落与环境因子关系的初步研究

Planktonic ciliate community and its relationship with environmental factors in southern South China Sea during autumn

根据2013年秋季（11月-12月）南沙群岛海域18个站位浮游纤毛虫和环境因子的调查资料,对浮游纤毛虫群落特征进行分析,并且探讨了影响浮游纤毛虫群落变动的主要环境因素。结果表明,共检出17种浮游纤毛虫,隶属于2目10属,砂壳目Tintinnida与寡毛目Oligotrichida。优势种包括三亚条纹虫Rhabdonella sanyahensis、锥形急游虫Strombidium conicum、杆状真铃虫Eutintinnus stramentus、酒瓶类铃虫Codonellopsis morchella、球形急游虫Strombidium globosaneum。浮游纤毛虫平均丰度为（36.5±3.8）ind./L（10-80 ind./L）,呈现斑块状分布,最大丰度出现在南沙群岛海域的中偏北部,其次在万安滩的东侧丰度值也较高,而在西北部、东北部和东南部的丰度值较低。浮游纤毛虫的水平分布可能与海洋环流有密切关系。此外,通过相关性分析和典范对应分析（canonical correspondence analysis,CCA）发现,南沙群岛海域浮游纤毛虫群落结构差异主要受水体营养盐水平与叶绿素a含量等环境因素的影响。

Based on samples collected with CTD water sampler at a depth of 5 m from 18 sites in southern South China Sea during later autumn, 2013, species composition and abundance of planktonic ciliate and its relationship with the environment variables were investigated. A total 17 species belonging to 10 genera and two orders （Tintinnida and Oligotrichida） were identified. Among them, there were five dominant species （ dominance Y≥0. 02） , including Rhabdonella sanyahensis, Strombidium conicum, Eutintinnus stramentus, Codonellopsis morchella, Strombidium globosaneum. The mean abundance of ciliate was （36.5 ±3.8） ind. /L （10 -80 ind. /L）. Ciliates abundance distribution presents a patchy distribution, and the distribution of planktonic ciliates may be closely related to ocean circulation. Canonical correspondence analysis demonstrated that the nutrient level and Chlorophyll a concentration were the most important factors affecting the spatial pattern of planktonic ciliate communities in southern South China Sea.