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

细菌，picocyanobacteria，真核picoplankton，nanoflagellate和纤毛虫丰度相互之间的关系和叶绿素a（Chl。对暖季31个表层沃茨水体的a）、总磷（TP）、总氮（TN）及TN/TP比值进行了调查。细菌和纤毛虫的丰度与TP、TN和Chl呈正相关。a与TN：TP比值呈负相关。TP和Chl的线性回归。a分别占细菌和纤毛虫丰度变异的51%和34%。在日本15个沃茨表层和原生动物中设置了聚氨酯泡沫单元（PFU）通过高清晰度电视监视器记录了PFU中挤压水中的（植生虫、动生虫、肉足虫和纤毛虫）（Chu-ou mushen THMC-21 BH/CH），其与HD摄像系统（Nikon HQ-130 C和PA-160）和显微镜（Olympus BH 2）连接。首次报道了日本湖泊原生动物的区系组成，并在霞浦湖6个围隔中调查了银对浮游生物群落的影响。异养nannofiagellate（HNF）丰度的9%的变异占枝藻（自上而下的效果）和细菌（自下而上的效果）丰度。丰富的微蓝细菌不能解释HNF丰度的变化，尽管众所周知HNF以微蓝细菌和细菌为食。自养鞭毛虫丰度的变化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.