Flagellate and ciliate distribution in sediments of a lowland river: relationships with environmental gradients and bacteria
Flagellate and ciliate distribution in sediments of a lowland river: relationships with environmental gradients and bacteria
复制标题
低地河流沉积物中鞭毛虫和纤毛虫的分布：与环境梯度和细菌的关系
DOI：
10.3354/ame031067
复制
发表时间：
2003
影响因子：
1.4
通讯作者：
H. Fischer
中科院分区：
文献类型：
--
作者：
B. Gücker;H. Fischer
人们普遍认为原生动物是微生物食物网中细菌的重要捕食者，但关于河床沉积物中原生动物丰度的数据有限。我们研究了六级低地河流（德国施普雷河）的移动和分层沙质沉积物中鞭毛虫和纤毛虫的丰度、群落结构和空间分布与环境梯度和细菌的关系。使用实时观察和定量普罗戈染色技术对鞭毛虫和纤毛虫进行定量和鉴定。鞭毛类的底栖沉积物丰度（中位数和四分位距）为 1900 个细胞 cm -3 （938 至 3363，n = 104），纤毛虫的丰度为 148 个细胞 cm -3 （29 至 363）。波多尼科动物、无色眼虫和拟毛纤毛虫（主要是蝉）在原生生物群落中占主导地位。随着分层沉积物中沉积深度的增加，原生生物丰度下降。在这些沉积物的深层中出现了微需氧到厌氧的群落。需氧食菌原生动物在流沙中盛行。前列腺菌群落似乎是由多种因素相互作用构成的，例如溶解氧、光穿透、细菌和沉积物成分。使用已公布的放牧率进行的估计表明，鞭毛虫和纤毛虫的密度太小，无法控制这些低地河流沉积物中的细菌密度。
It is generally assumed that protozoa are important predators of bacteria in the micro- bial food web, but limited data are available on protozoan abundance in streambed sediments. We investigated flagellate and ciliate abundance, community structure and spatial distribution in the shifting and stratified sandy sediments of a 6th order lowland river (River Spree, Germany) in rela- tion to environmental gradients and bacteria. Flagellates and ciliates were quantified and identified using live observation and quantitative protargol staining techniques. Abundances (median and interquartile range) were 1900 cells cm -3 of benthic sediment (938 to 3363, n = 104) in flagellates and 148 cells cm -3 (29 to 363) in ciliates. Bodonids, colorless euglenids and hypotrich ciliates, predomi- nantly Aspidisca cicada Muller, dominated the protistan community. Protistan abundance declined with increasing sediment depth in stratified sediments. A microaerophilic to anaerobic community occurred in deeper layers of these sediments. Aerobic bacterivorous protozoa prevailed in shifting sands. The prostistan community seemed to be structured by an interplay of factors, such as dissolved oxygen, light penetration, bacteria and sediment composition. Estimates using published grazing rates indicated that flagellate and ciliate densities were too small to control bacterial densities in these lowland river sediments.