A Comprehensive Evaluation of Herbivory by in Situ Assemblages of Pelagic Protists

远洋原生生物原位组合对草食性的综合评价

• 批准号: 9116301
• 负责人: Evelyn Sherr
• 金额: $ 21.57万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-11-15 至 1994-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9116301&HistoricalAwards=false
• 关键词: Comprehensive; Evaluation; Herbivory; Situ; Assemblages

One of the most urgent questions in biological oceanography at present is that of the fate of small phototrophs in pelagic food webs. The prevailing concept, based on both theoretical considerations as well as laboratory and field data, is that phagotrophic protists are the dominant predators of 5 um sized cells, and as well may consume a significant portion of the biomass production of larger phytoplankton. Most previous studies of protistan herbivory have involved either laboratory experiments with single species, primarily ciliates, or estimation of total microzooplankton grazing pressure on natural phytoplankton assemblages. A more complete picture of the magnitude and details of the component parts of this link in pelagic food webs in needed, especially with respect to the role of phagotrophic flagellates. Dr. Sherr and collaborators will investigate herbivory by pelagic flagellates and ciliates in the natural planktonic assemblages of Oregon coastal waters. Questions addressed will include: 1) Do phagotrophic protists have a greater grazing impact on 5 um sized phytoplankton than on cells 5 um? 2) What is the relative grazing impact of flagellates versus ciliates on phytoplankton? 3) Do rates of protistan herbivory show consistent day/night differences? 4) Do thresholds of prey density exist? 5) Does predation affect the cell division rates of phytoplankton? 6) Do phagotrophic protists show selective feeding among various phytoplankton taxa in situ?

生物学中最紧迫的问题之一 海洋学目前是小的命运， 浮游食物网中的光养生物。 流行的概念， 基于理论考虑和实验室 和现场数据，是食食性原生生物是主导 捕食者的5微米大小的细胞，以及可以消耗 大部分生物质生产 浮游植物 大多数关于原生动物食草动物的研究 涉及到实验室实验， 种，主要是纤毛虫，或估计总 微型浮游动物对天然浮游植物的摄食压力 集会更完整的图片的规模和 远洋食物中这一环节各组成部分的详细情况 需要的网络，特别是关于 食鞭毛虫 Sherr博士及其合作者将 浮游鞭毛虫和纤毛虫食草性研究 俄勒冈州沿海沃茨的天然浮游生物组合。 讨论的问题包括：1）食食性原生生物 对5微米大小的浮游植物的放牧影响比 在细胞5 um？2)相对放牧影响是什么 鞭毛虫和纤毛虫对浮游植物的影响3)做率 原生动物食草动物表现出一致的昼夜差异？四、 猎物密度的阈值存在吗？5)捕食会影响 浮游植物的细胞分裂率6)做食营养的 原生生物在各种浮游植物中表现出选择性摄食 原地分类群？