西太平洋和东印度洋砂壳纤毛虫暖水群落空间异质性研究

Tintinnids are planktonic ciliates with lorica. They are intermediate in the transfer of material and energy from microbial food web to classical food chain. Warm water tintinnid assemblage locates in the tropical and subtropical oceans between latitude 45 south and 45 north. This program will study the spatial heterogeneity of warm water tintinnid assemblage in western Pacific and eastern Indian Ocean aboard the open cruises of NSFC. The assemblage characteristics such as abundant species, LOD size classes and redundant species, dominant LOD size classes are studied in different parts of the study areas. We aim to elucidate vertical and horizontal heterogeneity of the warm water tintinnid assemblage. Vertical heterogeneity is the difference from surface to the bottom of euphotic zone (defined as 300 m in our study). Horizontal heterogeneity include (1) meso scale heterogeneity from the evolutional climax area to the shelf seas, and (2) large scale heterogeneity between western Pacific Ocean and eastern Indian Ocean. This study is part of the comparative study, which is the hot topic of marine ecology study. The output of this program will help understanding of the structure and functioning of the microbial food webs in tropical and subtropical oceans.

砂壳纤毛虫是具壳的浮游寡毛类纤毛虫，是微食物网中物质和能量向经典食物链传递的重要中介。暖水砂壳纤毛虫群落是处于热带亚热带海区(南纬45度和北纬45度之间)的群落。本项目拟搭乘国家自然科学基金委西太平洋和东印度洋共享航次，以砂壳纤毛虫高丰度种的丰度变化及比例、LOD径级和冗余种的数目的变化、优势LOD径级的变化等为具体研究内容，分析西太平洋和东印度洋砂壳纤毛虫暖水群落的空间异质性，包括：(1)垂直方向空间异质性，即从表层至真光层底部（约300 m）砂壳纤毛虫暖水群落的变化；(2)中尺度的水平方向空间异质性，即从演替顶极区域到外围，暖水群落的变化；(3)大尺度的水平方向空间异质性，即西太平洋和东印度洋之间砂壳纤毛虫暖水群落的差异。本项目的研究结果对理解热带和亚热带大洋微食物网结构和功能具有重要意义。

砂壳纤毛虫是单细胞的原生动物，隶属于纤毛门 - 旋毛纲 - 环毛亚纲 - 砂壳目，是浮游纤毛虫的重要组成部分。因为具有硬质的外壳，砂壳纤毛虫既便于保存，又便于观察和种类鉴定，是海洋浮游生物群落研究的模式类群，在全球各海区都有报道。在热带大洋中，砂壳纤毛虫群落呈现明显的多样性高、丰度低的特点。本项目通过对热带西太平洋和东印度洋以及印太交汇区的多次调查，探明了热带西太平洋和东印度洋海区砂壳纤毛虫的物种多样性；热带大洋区砂壳纤毛虫群落水平和垂直方向的空间异质性；以及两个海区砂壳纤毛虫群落间的连通性。本研究为进一步理解热带大洋海区微食物网结构空间变化提供了基础资料，为预测全球变化对热带海区浮游生态系统的影响提供了参考依据。