| 摘要: |
| 采用Ludox-QPS方法，研究了2011年8月采自长江口邻近海域9个站位沉积物中纤毛虫的群落结构及分布特点，并结合沉积环境进行综合分析。结果表明，表层8cm沉积物中底栖纤毛虫的平均丰度为（2782±1493）cells/10cm2，生物量为（10.06±6.41）μg C/10cm2。长江口海域北部站位的丰度和生物量呈从近岸向外海增加，南部的站位呈现相反的分布趋势。在垂直分布上，62%的底栖纤毛虫分布在表层2cm，12%分布在5-8 cm。本研究共检获纤毛虫106种，隶属于15纲/亚纲，24目，69属，前口纲在丰度及生物量上均为最优势类群（丰度占45.5%，生物量占56.4%），核残迹纲在生物量上居第二位。就食性来看，肉食性纤毛虫物种数最多（44种），其丰度和生物量所占比例也最高（40.3%，66.8%），但在长江口外站位（M1站），菌食性纤毛虫为最优势摄食类群。分析表明，研究海域底栖纤毛虫群落结构与底层水盐度最相关。聚类分析结果显示，由于较多量的伪钟虫属（Pseudovorticella）和原领毛虫属（Prototrachelocerca）种类出现导致长江口北部L1站的纤毛虫群落结构不同于其他站位。本研究所获底栖纤毛虫的丰度和生物量较东海离岸海域已有研究结果均高，表层8cm沉积物中纤毛虫的丰度约是上层30m水柱中浮游纤毛虫的116倍，生物量约是后者的150倍。基于目前黄东海有关底栖纤毛虫物种多样性的已有报道，其多样性在长江口离岸海域高于近岸潮间带，且在离岸海域东海低于黄海。 |
| 关键词: 长江口 底栖纤毛虫 多样性 现存量 分布 |
| DOI：10.11693/hyhz20200100004 |
| 分类号: |
| 基金项目:国家自然科学基金项目，41876171号。 |
|
| DIVERSITY AND COMMUNITY STRUCTURE OF BENTHIC CILIATES IN SEDIMENTS OF CHANGJIANG RIVER ESTUARY AND ITS ADJACENT AREAS IN SUMMER |
|
MENG Zhao-Cui1,2,3, XU Kui-Dong1,2,4,3
|
|
1.Department of Marine Organism Taxonomy and Phylogeny, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;2.Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology(Qingdao), Qingdao 266071, China;3.Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China;4.University of Chinese Academy of Sciences, Beijing 100049, China
|
| Abstract: |
| Distribution and community structure of benthic ciliates in the Changjiang (Yangtze) River estuary and its adjacent areas were investigated using Ludox density centrifugation and the quantitative protargol staining methods (Ludox-QPS). The relationships of the benthic ciliates with environmental factors were studied based on the sediment samples collected from nine stations in August 2011. Results show that the mean abundance of ciliates in the upper 8 cm of the sediments was (2782±1493)cells/10cm2 and the biomass was (10.06±6.41)μg C/10cm2. The abundance and biomass increased from inshore to offshore in the stations in the northern part of the estuary, while those in the southern part showed the opposite trends. In vertical distribution, 62% of benthic ciliates distributed in 0-2cm sediment depth, and 12% in the 5-8cm. In this study, 106 morphospecies were identified, belonging to 15 ciliate classes/subclasses, 24 orders and 69 genera. Prostomatea was the most abundant group accounting for 45.5% of the total abundance and 56.4% of the total biomass, followed by Karyorelictea in biomass. In species number, Carnivorous ciliates ranked the first at 44, taking 40.3% of the total abundance, and 66.8% of the total biomass. However, bacterivores was the most dominant feeding type outside the estuary. Statistical analysis revealed that for the abundance of ciliate species and benthic environmental variables, the highest correlation was with the bottom water salinity. The community structure of benthic ciliates in one station (L1, shallow at 18m, warm at the bottom, and high chlorophyll a) in the northern of the estuary was significantly different from the rest. The ciliate abundance and biomass in the upper 8cm of sediments were higher than those in the East China Sea, which was 116 times higher in the abundance than those in the upper 30m of water column from the estuary, and 150 times higher in the biomass than pelagic ciliates. The diversity of marine benthic ciliates was higher in the offshore area than in the intertidal area of the estuary, while the ciliate diversity in the offshore area was lower in the East China Sea than in the Yellow Sea. |
| Key words: Changjiang (Yangtze) River estuary benthic ciliates diversity standing crops distribution |
