海洋生态与环境科学重点实验室知识库

  砂壳纤毛虫是一类具纤毛的单细胞原生动物，隶属于纤毛门（Ciliophora）-旋毛纲（Spirotrichea）-环毛亚纲（Choreotrichia）-砂壳目（Tintinnida）。体长一般在20-200 μm之间。砂壳纤毛虫生活史简单，对环境变化响应十分迅速，不同种的外壳形态各异，便于保存观察和分类鉴定，因此，其常被作为研究海洋浮游生态的模式生物。砂壳纤毛虫是微型浮游动物的重要组成部分，主要摄食浮游硅藻、鞭毛虫和微微型浮游生物，在水体生态系统能量流动和物质循环中占重要地位。从极地至赤道海区，不同分布类型的种类组成了砂壳纤毛虫北方（南方）冷水群落、暖水群落和近岸群落。目前，对各分布类型砂壳纤毛虫分布和扩散的影响因子，以及不同砂壳纤毛虫群落的结构特征等问题的研究还不够深入。为解决上述问题，我们对北太平洋亚热带环流西北边缘砂壳纤毛虫群落的分布情况进行了调查。

  南北半球35-45°之间的海域是亚热带环流和亚极地环流间的过渡区，是研究海洋浮游生物地理分布非常重要的区域，但是目前尚没有任何关于砂壳纤毛虫过渡群落的报道。我们分别于2016年和2019年的夏季，通过两个横穿北太平洋的断面调查了砂壳纤毛虫群落的分布情况。在调查中共检出83种砂壳纤毛虫大洋种，其中41种为常见大洋种，分为5个类群：北方种、暖水种I型、暖水种II型、过渡种和广布种。加州波膜虫和克里夫氏波膜虫为过渡种；暖水种I型中一些种类如小瓮状虫、酒杯类管虫、网状网袋虫、太平洋真铃虫、管状真铃虫、简单原纹虫和斯廷细瓮虫等虽然分布广泛，但丰度高值出现在过渡区中，当温度低于15°C时丰度迅速降低甚至消失。与相邻区域相比，过渡区砂壳纤毛虫的种丰富度没有明显的增加。24-28 μm口径组的砂壳纤毛虫种类在各群落中均占主导地位，但该口径组的丰度比例从北方群落（67.09%）到过渡群落（48.38%），再到暖水群落（22.82%）逐渐降低。本研究证实了砂壳纤毛虫过渡群落的存在，可以作为北太平洋过渡区北侧边界的指示类群。

  我们于2019年夏季沿黄、东海至西太平洋跨越黑潮主轴的一个断面（122-145°E）对表层砂壳纤毛虫群落进行调查，研究了黑潮与相邻大洋中砂壳纤毛虫群落的差异。该断面砂壳纤毛虫的丰度范围为3.95-131.94 ind./L，种丰富度范围为6-24。共发现砂壳纤毛虫21属42种，有7种优势种，分别为缩短原纹虫、杆状真铃虫、卢氏真铃虫、镯形囊坎虫、管状真铃虫、长形旋口虫和斯廷细瓮虫。根据各种的丰度分布模式，将33种常见种划分为4个类群：类群I为广布类群，丰度最高；类群II主要出现在断面中部，受黑潮影响较大，其中酒杯类管虫可以作为黑潮的指示种；类群III主要出现大洋海区；类群IV则主要分布于近岸海区，丰度较低。该断面的砂壳纤毛虫群落可以分为大洋边缘群落、黑潮群落和大洋群落，在黑潮群落中有不同于其两侧的种类。该研究结果有助于理解黑潮对浮游生物地理分布的影响。

  目前对于西太平洋海区浮游纤毛虫的垂直分布已有部分研究，但是中尺度涡对浮游纤毛虫垂直分布影响的报道还是空白。我们于2019年夏季对西太平洋一反气旋暖涡中的浮游纤毛虫群落结构进行了调查，发现暖涡核心站位和暖涡边缘站位浮游纤毛虫的垂直分布模式分别为“双峰型”和“单峰型”，无壳纤毛虫是其主要组成类群，砂壳纤毛虫占比小于25%。10-20 μm粒级无壳纤毛虫在各水层中均属于优势类群，丰度和丰度比例远大于其他粒级，暖涡核心站位其丰度比例略低于暖涡边缘站位。砂壳纤毛虫不同种类对于暖涡的响应也不相同，其中酒杯类管虫丰度较大，由于暖涡的影响丰度高值区明显下沉，该种对研究海洋水动力过程有重要指示意义。

    Tintinnids are single-celled protozoans which belong to the Ciliophora- Spirotrichea-Choreotrichia-Tintinnida. Tintinnid size is generally between 20-200μm. It has a simple life history and responds quickly to environmental changes. Different tintinnid species have different lorica, which are convenient for preservation, observation and classification and identification. Therefore, it is of great significance to regard it as a model organism for studying marine plankton ecology. As an important part of the microzooplankton in the water microbial food web, tintinnid mainly feed on planktonic diatoms, flagellates and picoplankton, and play an important role in the energy flow and material cycle of the water ecosystem. From polar to equatorial regions, different types of tintinnid species formed the boreal (austral) cold water community, warm water community and neritic community. However, the factors affecting the distribution and spread of different types of tintinnid species, as well as the structural characteristics of different tintinnid communities are not sufficiently studied. In order to solve these problems, this paper investigated the distribution of tintinnid in the northwestern margin of the North Pacific subtropical gyre.

    Located between 35-45° latitude in both hemispheres, Transition Zone is an important region in the planktonic biogeography of the sea. However, to the best of our knowledge, there has been no report on the existence of tintinnid Transition Zone community. In this research, tintinnids across two major transects across the North Pacific was investigated in summer 2016 and 2019. A total of 83 oceanic tintinnid species were identified, 41 of which were defined as common oceanic species. They were further divided into 5 groups: Boreal, Warm water type I, Warm water type II, Transition Zone and Cosmopolitan species. Tintinnid Undella californiensis and U. clevei were Transition Zone endemic species. Other tintinnid species such as Amphorides minor, Dadayiella ganymedes, Dictyocysta mitra, Eutintinnus pacificus, E. tubulosus, Protorhabdonella simplex and Steenstrupiella steenstrupii were most abundant in Transition Zone but spread over a much larger distribution region. Species richness showed no obvious increase in the Transition Zone. Tintinnid lorica oral diameter (LOD) size-class was dominated by 24-28 μm, but the dominance decreased from 67.09% in Boreal community to 48.38% in Transitional community and then to 22.82% in Warm water community. Our research confirmed the existence of Transition Zone tintinnid community. The abrupt disappearance of Warm water species type I in below 15°C suggested that this group could be used an indicator of the northern boundary of North Pacific Transition Zone.

    For the Western Pacific Ocean planktonic ciliate vertical distribution has been part of the study, but under the influence of mesoscale eddy planktonic ciliates vertical distribution changes has not related. A survey of the Western Pacific Ocean warm anticyclonic eddy was conducted in the summer of 2019, which found planktonic ciliates vertical distribution patterns were different in the warm eddy core stations (bimodal-peak) and warm edge eddy stations (deep chlorophyll a maximum peak, DCM-peak), respectively. Aloricate ciliates was the main composition of planktonic ciliates, tintinnid accounted for less than 25%. The 10-20 μm LOD size-class aloricate ciliates belonging to the dominant group ranged from the surface to 1000 m. The abundance and abundance proportion of aloricate ciliates in this size-class were much higher than those in other LOD size-classes. The abundance proportion of 10-20 μm LOD size-class aloricate ciliates in the warm eddy core stations was slightly lower than that in the eddy edge stations. Different tintinnid species have different responses to the warm eddy. Dictyocysta mitra was relatively abundant and sinked significantly in the area with high abundance under the influence of warm eddy. This species is of great significance for the study of marine hydrodynamic processes.

目  录

第1章 引言........................................................................ 1

1.1 砂壳纤毛虫研究的生态学意义................................................ 1

1.1.1 壳的生态学意义................................................................. 2

1.1.2 在海洋浮游生态系统中的作用......................................... 3

1.1.3 研究海洋浮游生物的模式生物......................................... 4

1.2 砂壳纤毛虫的生物地理学研究................................................ 4

1.2.1 海洋浮游生物地理分布..................................................... 5

1.2.2 砂壳纤毛虫的生物地理分布............................................. 6

1.2.3 不同砂壳纤毛虫群落研究现状......................................... 9

1.3 本论文的研究海区、方法及目的.......................................... 10

1.3.1 研究海区........................................................................... 10

1.3.2 研究方法........................................................................... 10

1.3.3 研究目的........................................................................... 11

第2章 北太平洋过渡区夏季表层水砂壳纤毛虫群落的水平分布............................................................................ 13

2.1 材料与方法.............................................................................. 13

2.2 结果.......................................................................................... 14

2.2.1 整体概述........................................................................... 14

2.2.2 常见大洋种的分布模式................................................... 19

2.2.3 大洋种的丰度和种丰富度............................................... 20

2.2.4 大洋砂壳纤毛虫群落....................................................... 20

2.3 讨论.......................................................................................... 30

2.3.1 过渡种............................................................................... 30

2.3.2 暖水种I型........................................................................ 30

2.3.3 过渡区的范围................................................................... 31

2.3.4 过渡区的砂壳纤毛虫群落............................................... 32

2.3.5 两条断面差异................................................................... 32

2.4 小结.......................................................................................... 33

第3章 夏季黄、东海至西太平洋断面表层砂壳纤毛虫群落的变化............................................................................ 34

3.1 材料与方法.............................................................................. 34

3.2 结果.......................................................................................... 35

3.2.1 温度、盐度和叶绿素a浓度沿断面的变化................... 35

3.2.2 砂壳纤毛虫种类组成、种丰富度和丰度....................... 35

3.2.3 砂壳纤毛虫的分布模式................................................... 36

3.2.4 各个类群种丰富度、丰度和丰度比例沿断面的变化... 36

3.2.5 砂壳纤毛虫总丰度和环境因子的关系........................... 37

3.3 讨论.......................................................................................... 41

3.4 小结.......................................................................................... 42

第4章 夏季暖涡对西太平洋浮游纤毛虫群落垂直分布的影响................................................................................ 43

4.1 材料与方法.............................................................................. 43

4.2 结果.......................................................................................... 44

4.2.1 整体概况........................................................................... 44

4.2.2 浮游纤毛虫垂直分布....................................................... 48

4.2.3 不同粒径无壳纤毛虫的垂直分布................................... 49

4.2.4 砂壳纤毛虫的垂直分布................................................... 50

4.3 讨论.......................................................................................... 54

4.3.1 浮游纤毛虫的垂直分布................................................... 54

4.3.2 不同粒级的无壳纤毛虫垂直分布................................... 54

4.3.3 砂壳纤毛虫的垂直分布................................................... 55

4.4 小结.......................................................................................... 55

第5章 结论与展望.......................................................... 57

5.1 本论文在西太平洋不同海区资料的汇总.............................. 57

5.2 主要结论.................................................................................. 57

5.3 创新点...................................................................................... 58

5.4 展望.......................................................................................... 59

参考文献............................................................................ 60

附录.................................................................................... 71

致  谢................................................................................ 89

作者简历及攻读学位期间发表的学术论文与研究成果 91