中国河口轮虫动物分类学研究及其物种多样性评估

The rotifers (Phylum Rotifera) are a diverse assemblage of metazoan pseudocoelomate worms, usually much less than 1 mm in length, widely distributed in various aquatic habitats, and play important roles in the cycle of mass and energy fluxes in estuarine ecosystems. Rotifer taxonomic research in China lag far behind currently, 《Freshwater Rotifera Fauna of China》 published in 1961 still is the main reference for rotifer taxonomy, which lacked of brackish-water and marine species of estuarine ecosystem, and species richness was underestimated severely compared with other countries with more rotifer taxonomic studies. Our previous research on the rotifer taxonomy of 3 wetlands on Qi'ao Island in the Pearl River estuary found lots of new species and new records for China. It indicated that most published paper on estuarine rotifers aimed for ecological study and mostly sampled with plankton nets in main streams of estuaries severely underestimated the biodiversity of the estuary rotifers. This application is aimed to sample all kinds of biotopes in 5 typical estuary of China to examine free planktonic species, macrophytes periphytic species, benthos and sediment species comprehensively, using morphological taxonomy (including scanning electron microscopy observation and numerical taxonomy) combined with molecular taxonomy methods to find new species to nature, new record for China, analyze phylogenic relationship and revise the taxonomic system, finally, establish the database of estuarine rotifer species list, and their ecological characteristics, geographical distribution, etc. and make an objective evaluation on rotifer biodiversity. Our results will provide fundamental taxonomic and ecological data for biodiversity conservation of estuarine rotifers, rational utilization of biological resources, ecological investigation and environmental assessment.

轮虫是体型较小的一类后生假体腔动物，广泛分布于各种水生生境，亦为河口生态系统的重要组成部分。目前我国轮虫分类学研究相对滞后，主要参考文献仍为1961年的《中国淡水轮虫志》等，缺乏河口咸淡水和海洋类群的研究，且物种多样性远低于分类学研究较多的国家。本团队前期仅调查了珠江口3个生境中的轮虫发现了大量的新物种和新纪录，说明之前采样方法和调查生境都较单一的生态学研究严重低估了河口轮虫的物种多样性。针对上述现状，本项目拟以我国5个典型河口为调查对象，全面、系统的调查河口各种生境中不同生活方式的轮虫，利用形态分类（扫描电镜和数值分类法）与分子鉴定相结合的方法，发现新物种和国内新纪录、研究物种进化关系、修订分类系统，构建我国河口轮虫物种名录、生态学特征及地理分布等信息的数据库，并对轮虫现存量做出客观评估，为我国河口生境中的轮虫生物多样性保护、资源合理利用、生态调查与环境评估等提供系统的分类和生态学资料。

轮虫是体型较小的一类后生假体腔动物，广泛分布于各种水生生境，亦为河口生态系统的重要组成部分。目前我国轮虫分类学研究相对滞后，缺乏河口咸淡水和海洋类群的研究，严重低估了其物种多样性。本项目针对上述现状，对我国5大河口区域（辽河口、黄河口、长江口、珠江口和南渡江口）进行了2个批次大范围的调查，共采集270个样品。（1）构建了我国河口轮虫物种名录，共观察到单卵巢类轮虫280种（辽河口59种、黄河口86种、长江口115种、珠江口168种、南渡江口125种）。发现轮虫新种28种（3种已正式命名）、国内新纪录种46种（5种已发表）。同时对部分疑难物种进行了分子鉴定及系统进化的分析；（2）完成了我国河口轮虫栖息生境理化数据信息库的构建；（3）使用四种生物多样性指数对各河口轮虫的物种多样性进行了评估，其物种多样性大小顺序为：珠江口>南渡江口>长江口>黄河口>辽河口。按照任务书指标，已完成研发内容。本项目已发表论文3篇，包括2篇SCI论文和1篇中文核心期刊，另1篇SCI论文已接受待刊，1篇SCI论文已投稿在审，1篇英文初稿已完成待投稿，培养硕士研究生2名。参加国际和国内会议2次。本项目的完成，大大丰富了我国轮虫的物种多样性，也为我国河口轮虫生物多样性保护、资源合理利用、生态调查与环境评估等提供了系统的分类和生态学资料。