黄海沉积物中纤毛虫生物多样性与分布特征

纤毛虫是近海沉积物中多样高且重要的原生动物类群，是揭示微型生物多样性和地理分布的模式生物。迄今对海洋沉积物中纤毛虫多样性的认识主要来自潮间带。由于技术局限和研究欠缺，对于近海，尤其是离岸海域沉积物中纤毛虫的分类构成、多样性及分布特点尚缺基本了解。本研究拟选择黄海这一典型海域，通过对沉积物多生境条件的建立和培养，在传统分类学基础上，通过对沉积物中纤毛虫的定量提取与定性分析，结合18S rDNA高通量测序及荧光标记-电镜观察(FISH-SEM) 这一新方法，搞清黄海沉积物中纤毛虫的物种及分子多样性构成，揭示新物种和隐存多样性；阐明纤毛虫随环境和地理距离的多样性构成及分布特点；厘清纤毛虫的物种-丰度关系，估计黄海沉积物中纤毛虫的潜在物种多样性。本研究系新技术方法在底栖纤毛虫多样性研究中的应用，将为近海底栖纤毛虫多样性研究提供一份翔实可靠的本底资料，为未来深远海相关研究提供一份可资借鉴的工作示范。

Ciliates are a morphologically high diverse and ecologically important group of protozoa in sediments of shallow seas and have been considered as model organisms in evaluating microbial biodiversity and biogeography. So far our knowledge of ciliate diversity in marine sediments is largely restricted to that from intertidal zone. Due to technical and taxonomic impediments, the species composition, diversity and distribution of ciliates in marine sediments, in particular those in offshore areas are largely not known. In this project, with direct isolation of ciliates from marine sediments, we intend to establish successive and diversified cultivations by incubating sediment samples under a variety of conditions to stimulate the growth of rare and encysted ciliates. By using modern taxonomic techniques, the Ludox centrifugation combined with quantitative protargol stain (Ludox-QPS), and the high-throughput sequencing of 18S rDNA in combination with the FISH-SEM method, we aim to (i) uncover the species and molecular diversity of ciliates in offshore sediments of the Yellow Sea; (ii) discover new and cryptic species of ciliates; (iii) elucidate the diversity and distribution of ciliates along with benthic environmental factors; and (iv) estimate the species-abundance relationship and the potential species diversity of benthic ciliates in the Yellow Sea. This study will be the first combined utilization of newly developed methods to uncover the hidden diversity of marine benthic ciliates. The project will supply the first-hand data to ciliate diversity in shallow sea sediments and lead the way to deep-sea research on ciliate diversity.