潮间带纤毛虫原生动物和小型底栖动物生态学研究

IOCAS-IR > 海洋环流与波动重点实验室

	潮间带纤毛虫原生动物和小型底栖动物生态学研究
其他题名	Ecological studies of ciliated protozoa and meiofauna in marine sediments of intertidal area
	杜永芬
学位类型	博士
	2008-06-14
学位授予单位	中国科学院海洋研究所
学位授予地点	海洋研究所
关键词	底栖纤毛虫小型底栖动物底栖微食物网 Ludox -qps技术污染监测
摘要	微型和小型底栖动物是底栖微/小食物网的重要构成。相对浮游生态系统, 迄今国际间对底栖食物网的认知极为欠缺。这一方面是由于微型生物形态和功能上的复杂性和多样性, 另一方面原因在于研究方法的障碍—主要是微型和小型底栖动物的定量提取和定性分析。本研究首先进行了方法学改良, 并应用新方法对底栖微食物网的重要功能类群—纤毛虫原生动物和小型底栖动物进行了不同生境的周年按月采样, 定性及定量研究的同时, 联系环境因子对微型和小型底栖生物的环境监测进行了探讨。微型和小型底栖生物的定量研究首先涉及到目标生物在沉积物中的有效提取, 目前硅胶液提取是普遍使用的方法, 其中Ludox液主要应用于小型生物, 它不但价格便宜而且比重合适, 因此在常规生态研究中被广为接受。不过, Ludox易与于海水中的阳离子产生凝结而无法直接用于微型生物; 目前唯一直接应用于微型生物提取的是Percoll硅胶液, 但其昂贵的价格使其在常规生态研究中受到极大限制。本研究以价格低廉的Ludox 硅胶液结合定量蛋白银染色 (QPS) 技术开发了一种新的方法, 即Ludox-QPS法。主要流程为: 样品采集与固定、淘洗/稀释降盐、Ludox密度梯度离心、过滤浓缩和琼脂包埋, QPS染色、永久封片及鉴定计数。添加已知数量的纤毛虫至无生物底泥的重获实验表明, 该密度梯度离心的提取率大于94%; 该方法对自然沉积物中纤毛虫的提取率达97.6%, 对沙质、泥沙质和泥质中海洋线虫的提取率分别达97%、96.9% 和97.8%。对比实验表明, 经QPS制片获得的小型动物的丰度和类群数量与传统方法相当或更高, 尤其当小个体虫体占优势时, 该法显示出较传统方法 (导致数量低估) 更为明显的定量优越性。该方法除用于纤毛虫和小型动物的定量分析外, 还具有较高的分类分辨率, 染色后的纤毛虫原生动物大多类群可鉴定到属, 部分可鉴定到种, 以此可在群落水平上研究其生态作用。根据新开发的Ludox-QPS技术, 在大沽河潮间带依据盐度梯度选定2个站位 (IIQ和营海) 进行了周年按月采样, 对底栖纤毛虫和小型底栖动物进行了定量研究。纤毛虫原生动物在IIQ和营海的年平均丰度分别为2236 inds./10 cm2 和935 inds./10 cm2 (28 inds./ml 和12 inds./ml), 平均生物量分别为119.1 gC/10 cm2和54.2 gC/10 cm2 (1.5 gC /ml 0.7 gC/ml)。丰度的季节变化趋势为: 春天 > 秋天 > 夏天 > 冬天。垂直分布上, 在营海分布于表层0-0.5 cm 的比例为57.1%, 分布于0.5-2 cm、2-4 cm和4-8 cm比例分别为23.1%、11.4% 和8.5%; 13个月中除12月份外, 4-8 cm均有一定数量的纤毛虫分布; 而在IIQ, 97% 的纤毛虫分布在0-0.5 cm, 分布在0.5-2 cm、2-4 cm和4-8 cm比例分别为2.4%、0.4%和0.2%, 4-8 cm的分布只发生在春季和秋季。纤毛虫的多样性季节变化明显, 春秋季物种丰富, 两个站点每毫升沉积物的平均物种数分别为18和6。Two-Way Crossed ANOSIM 分析表明纤毛虫群落在月份间和站点间的差异极其显著。Pseudochilodonopsis sp., Chilodontopsis sp., Euplotes sp.及Prorodon sp.是表征两个生镜中纤毛虫群落的主要类群。同时, 发现了14个小型生物类群, 其中线虫在IIQ和营海的丰度优势度分别为97.4% 和78.6%。小型动物在IIQ和营海的年平均丰度分别为4793 inds./10 cm2和8915 inds./10 cm2 (60 inds./ml和111 inds./ml), 其生物量分别为1068.8 gC /10 cm2和1790 gC /10 cm2 (13.4 gC/ml和22.4 gC/ml)。小型底栖动物的丰度在IIQ的季节变化为: 夏季 (7888 inds./10cm2) > 秋季 (5447 inds./10cm2) > 春季 (3731 inds./10cm2) > 冬季 (2780 inds./10cm2); 在营海则完全相反: 冬季 (15579 inds./10cm2) > 春季 (10691 inds./10cm2) > 秋季 (6611 inds./10cm2) > 夏季 (4667 inds./10cm2)。小型底栖动物和纤毛虫的相对重要性存在明显的区域和季节差异。纤毛虫原生动物、小型动物及环境因子的相关分析表明, 纤毛虫的丰度和多样性与温度和盐度及有机质含量显著相关, 与小型动物没有显著相关性; 群落结构分析表明, 温度、有机质和小型动物的丰度的组合与纤毛虫群落丰度的相关系数为0.345; 盐度、脱镁叶绿素、有机质和小型动物生物量的组合与纤毛虫群落多样性的相关系数为0.403。依据海洋线虫和桡足类的比值 (N/C) 推测, IIQ 可能存在严重的有机污染, 营海则存在明显的季节波动, 8月和9月及2月可能是污染最严重的季节, 这种状况在纤毛虫群落结构的CLUSTER聚类中得到验证。虽然目前尚没有形成有关微型底栖生物-纤毛虫原生动物的污染检测的直接依据, 但本研究说明纤毛虫群落的确对环境污染具有一定的感应度, 而且这种感应和利用小型生物的主要类群估算的污染检测 (N/C) 存在一定程度的关联。 90年代早期有关青岛湾有机污染带的研究表明, 经彻底截污后, 其环境状况向良性发展。进一步了解该湾的健康状况, 2006.5-2007.5月对该湾沙质和泥沙质的小型动物进行周年按月采样。小型动物在泥沙质和砂质沉积物中的年平均丰度分别为4853 ± 1292 inds./10 cm2和1528 ± 569 inds./10 cm2; 年平均总生物量分别为1434.1 ± 897.0 gC /10cm2和720.7 ± 353.8 gC/10cm2。沙质底小型生物的丰度季节波动明显, 6月份和12月份最高, 3月份和9月份最低; 泥沙质季节波动不明显, 6月份最高。两个站点均有48%的小型动物分布在0-0.5 cm 表层, 海洋线虫在表层的分布比例分别为48% (泥沙质) 和34% (砂质)。共检获14个小型动物类群, 其中线虫在泥沙质和砂质沉积物中的年平均丰度分别4619 ± 1255 inds./10cm2和1014 ± 376 inds./10cm2, 其丰度优势度分别为95.2%和66.4%。其它在丰度上占优势的类群, 泥沙质依次为多毛类 (1.5%)、甲壳幼体 (1.5%) 和桡足类 (0.7%); 沙质依次为: 甲壳类幼体 (12.6%)、腹毛类 (8.3%) 和桡足类 (6.2%)。CLUSTER聚类分析表明, 泥沙质和和砂质中小型生物的丰度组成具有64%的相似性。BIOENV分析表明, 温度、盐度、中值粒径和粘土粉砂含量的组合最能解释不同月份之间和不同站位间的差异, 其相关系数为0.614。依据小型生物的丰度和类群组成, 表明泥沙质底尚存一定的有机污染。
其他摘要	Micro- and meiofauna are important components in benthic microbial food web. In comparison with the pelagic ecosystem, relatively less information is available on the benthic habitats. This can be partially explained by the complex in ecological functions and morphological diversities of these organisms, and methodological shortcomings, especially for the extraction of microorganisms from marine sediments for quantitative and qualitative analysis. Methodological experiments were conducted firstly and a new method-Ludox-QPS technique -was developed. Using the protocol, ciliated protozoa and meiofauna, were studied monthly at intertidal stations during one year, meanwhile the community was analyzed with environmental factors. Ludox has been widely applied to the extraction of meiobfauna, while Percoll is the only effective silica directly used for marine microbenthos. However, the high cost and low density limitation of Percoll hamper its wide application in routine ecological studies. A new approach namely Ludox-QPS method was developed using the very cheap Ludox replacing the rather expensive Percoll to extract ciliates from marine sediments for enumeration and identification. The protocol consists of sample preservation, desalinization by elutriation, organism extraction by Ludox centrifugation, preparation with the QPS and enumeration and identification under a microscope. The extraction efficiency was initially tested by recovering a known number of ciliates added to azoic sand and mud and over 94% of test ciliates were obtained. Two reference ciliates and nematodes from marine natural sediments were selected for evaluation. The method showed 97.6% for marine ciliates from sand and 97% of entire abundance of nematodes from sand 96.9% from muddy sand and 97.8% from mud. The high extraction efficiencies for both ciliates and nematodes indicated the method allowed for simultaneous enumeration of micro- and meiofauna. The comparison experiments showed that the abundance of meiofauna from QPS were higher than that from routine method using sieves. Especially when a large number of nematodes with smaller size (150-200×10-15 m) occurred, the QPS method showed much quantitative advantage for the estimation of meiofaunal importance in benthic microbial food web. Furthermore the method fulfils to enumerate ciliates with good taxonomic resolution, hence the ecological importance could be conducted in community Level. Using the Ludox-QPS method, the quantitative importance of benthic ciliates and meiofauna collected from two sites (St. IIQ & St. Y) of an intertidal area was carried out monthly in one year and analyzed with the environmental factors. The average annual abundances of ciliates were 2236 inds./10 cm2 and 935 inds./10 cm2 in St. IIQ and St. Y (28 inds /ml and12 inds /ml)), and the seasonal trend was spring > autumn > summer > winter, and the pattern is also found in diversity. 57.1% of ciliates in Sta. Y were distributed in 0 - 0.5 cm, the proportion in 0.5 - 2 cm, 2 - 4 cm and 4 - 8 cm were 23.1%、11.4% and 8.5% respectively, ciliates occured in 4-8 was found in each month except for December; While in Sta. IIQ, 97% of ciliate lives in 0-0.5 cm, the proportion in deeper sediments were 2.4%、0.4% and 0.2% resoectively. The occurrence in 4-8 cm was only found in spring and autumn.Two-Way Crossed ANOSIM test that there is significant difference in ciliated community between sites and seasons. Pseudochilodonopsis sp., Chilodontopsis sp., Euplotes sp and Prorodon sp. were the main dominant species which contributed to the community difference. Meanwhile, 14 meiofaunal groups were sorted, with the average annual abundances of 4793 inds./10 cm2 and 8915 inds./10 cm2 (60 inds./ml and 111 inds./ml) in St. IIQ and St. Y, respectively. The annual average biomass were 1068.8 gC /10 cm2 and 1790 gC /10 cm2 (13.4 gC/ml and 22.4 gC/ml) The seasonal trend of abundance in St. IIQ was summer (7888 inds./10cm2) > autumn (5447 inds./10cm2) > spring (3731 inds./10cm2) > winter (2780 inds./10cm2), while the trend in St. Y was in reverse: winter (15579 inds./10cm2) > spring (10691 inds./10cm2) > autumn (6611 inds./10cm2) > summer (4667 inds./10cm2).The data suggested that the quantitative importance of benthic ciliates and meiofauna was related to the habits and seasons. The analysis between ciliates and environmental factors showed that ciliate abundance and diversity were significant related to the temperature, salinity and organic matter. The combination of temperature, organic matter and meiofaunal abundance contributed 34.5% to the ciliated community difference in abundance. The combination of salinity, Ph-a, temperature organic matter, and meiofaunal biomass accounted for 40.3% for the difference in ciliate diversity. Benthic studies concerning the pollution at Qingdao Bay in 1990s of last century showed that its environments had been improved. To learn the condition of the Bay after twenty years of developments in Qingdao, meiofauna was sampled in silt-sand and sand sediments (St-S & S) from May, 2006 to May, 2007. The annual average abundance in St-S and S were 4853 ± 1292 inds./10 cm2 and 1528 ± 569 inds./10 cm2 respectively, and the annual biomass were 1434.1 ± 897.0 gC /10cm2 and 720.7 ± 353.8 gC/10cm2. The seasonal pattern in abundance was only found in sand. There were two peaks in June and September. 48% of meiofauna were occurred at 0 - 0.5 cm in the two stations, the percentage for nematodes in St. and S were 48% and 34 % respectively in this surface layer。14 meiofauna groups were found, nematodes were contributed 95.2% and 66.4% to the total meiofauna abundance。The other dominant groups in silt sand were Polychaeta (1.5%), Nauplii (1.5%) and Copepoda (0.7%); Nauplii (12.6%), Gastrotricha (8.3%) and Copepoda (6.2%) were the dominant groups besides Nematoda in S. The similarity was about 64.01% between the meiofaunal abundance in the two stations resulted from the CLUSTER analysis. The combination of temperature, salinity, medium size and the content of silty and clay could explained the difference using the analysis of BIOENV, and the coefficient were 0.614. Some pollution was existed in St-S considering the meiofaunal abundance and composition.
页数	143
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/647
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	杜永芬. 潮间带纤毛虫原生动物和小型底栖动物生态学研究[D]. 海洋研究所. 中国科学院海洋研究所,2008.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
10001_20051800681202（6771KB）			限制开放	--	浏览