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

生物海洋学中最紧迫的问题之一 目前是小型光养生物的命运， 食物网 流行的概念，基于两个理论 考虑因素以及实验室和现场数据， 食食性原生动物是5 μ m大小的优势捕食者 细胞，并且也可以消耗大部分的细胞。 大型浮游植物的生物量生产。 大多数先前 原生动物食草动物的研究涉及两个实验室， 实验与单一物种，主要是纤毛虫，或 微型浮游动物对自然界的摄食压力估计 浮游植物群落更完整的图片 这一联系的组成部分的规模和细节， 浮游食物网的必要性，特别是在 噬食性鞭毛虫的一部分 夏皮罗博士及其合作者将 调查浮游鞭毛虫和纤毛虫的食草性 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)什么是相对放牧的影响 鞭毛虫与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？4)做 存在猎物密度阈值吗5)捕食是否会影响 浮游植物的细胞分裂率6)食食性原生生物 在不同的浮游植物类群中显示出选择性进食？

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. Shapiro 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?