The distribution of the role of protozoa (flagellates) in lakes.

细菌、微蓝藻、真核生物微浮游生物、纳米鞭毛虫和纤毛虫的丰度及其与叶绿素a （Chl）的关系。a)调查了31个热带暖季水体的总磷（TP）、总氮（TN）和TN: TP比值。细菌和纤毛虫的丰度与TP、TN和Chl呈显著正相关。a与TN: TP比呈负相关。TP和Chl的线性回归。A分别占细菌丰度和纤毛虫丰度变异的51%和34%。异养型纳米鞭毛虫的丰度与细菌的丰度无关。在日本15个水域的表层设置聚氨酯泡沫装置（PFU），通过高清晰度电视监视器（竹乌木参THMC-21BH/CH）与高清摄像机系统（尼康HQ-130C和PA-160）和显微镜（奥林巴斯BH2）连接，记录PFU挤压水中的原生动物物种（植马甲、zoomastigophora、sarcodina和ciliata）。本研究首次报道了日本湖泊中原生动物的区系。研究了鲢鱼对霞浦湖浮游生物群落的影响。异养纳米藻（HNF）丰度变异的9%是由支藻（自上而下的效应）和细菌（自下而上的效应）丰度引起的。尽管众所周知HNF以细菌和花青菌为食，但花青菌丰度并不能解释HNF丰度的变化。自养鞭毛虫丰度的变异与鱼类密度和溶解无机氮量密切相关。

Relationships of bacterial, picocyanobacterial, eucaryotic picoplankton, nanoflagellate and ciliate abundances to each other and to chlorophyll a (Chl. a), total phosphorus (TP), total nitrogen (TN) and TN : TP ratio in 31 epilimnetic waters during the warm season were investigated. The abundances of bacteria and ciliates were postitively correlated with TP,TN and Chl. a, and negatively with TN : TP ratio. Linear regressions on TP and Chl. a accounted for 51% and 34% of the variability in bacterial and ciliate abundances, respectively. The abundance of heterotrophic nanoflagellates was not correlated with that of bacteria.Polyurethane foam units (PFU) were set in the epilimnion of 15 Japanese waters and protozoan species (phytomastigophora, zoomastigophora, sarcodina and ciliata) in the squeezed water from the PFU were recorded through a high-definition (HD) TV monitor (Chu-ou mushen THMC-21BH/CH), which was connected with a HD video camera system (Nikon HQ-130C and PA-160) and the microscope (Olympus BH2) . The fauna of the protozoa in Japanese lakes was reported for first time by the present study.The effects of silver carp on plankton communities were investigated with 6 enclosres set in Lake Kasumigaura. The 9% of the variability in heterotrophic nannofiagellate (HNF) abundance was accounted by both cladoceran (top-down effect) and bacteria (bottom-up effect) abundanes. Picocyanobacteria abundanec did not account for the variability in HNF abundance, although it is well known that HNF feeds on picocyanobacteria as well asbacteria. The variability in autotrophic flagellate abundance was closedly related with both the fish density and the dissolved inorgenic nitrogen amount.