Selective feeding by mucous-net filter feeders on the ocean's smallest organisms

粘液网滤食动物对海洋最小生物的选择性摄食

• 批准号: 1537201
• 负责人: Kelly Sutherland
• 金额: $ 23.95万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1537201&HistoricalAwards=false
• 关键词: Selective; feeding; mucous; net; filter

The surface of the ocean is dominated by microscopic plants and animals called picoplankton, which are at the base of the marine food web. Jelly-like animals called appendicularians specialize in feeding on these miniature organisms by filtering large quantities of water using nets made out of mucus. In the past, it was thought that appendicularians eat anything that passes through the mucous net, but new work shows that feeding may be selective. The most abundant group of microorganisms in the ocean, called SAR 11, seems to evade the appendicularian, while similar-sized photosynthetic microbes are captured. In this study, a series of lab and field experiments will be conducted in Oregon, USA, and Villefranche-sur-mer, France, to uncover the mechanisms for selectivity. The research will test the effect of particle shape (e.g. spherical vs. ellipsoidal), adhesion properties of particles to mucous meshes, and the role of hydrodynamics. It will focus on the cosmopolitan appendicularian Oikopleura dioica, an important grazer of picoplankton. Results will be important for understanding the role of mucous-net filter feeders in shaping the structure of the ocean's microbial community as well as biogeochemical cycling. The project will support an early-career faculty member, will provide training and mentoring for one PhD student and two undergraduates, involves collaboration with scientists in France and Israel, and will engage the public through exhibits and images to be displayed at the Hatfield Marine Science Visitor Center and Charleston Marine Life Center. Picoplankton occur at densities of up to a million per mL and numerically dominate the upper ocean prey field. Since appendicularians influence pico- and nano-particle flux through their high filtration rates and the production of mucous aggregates, selective grazing will have important ramifications for microbial loop dynamics and vertical flux. Therefore, this work will provide insights into the mechanisms governing bacterioplankton community structure in the upper ocean and increase understanding of microbial-metazoan food web interactions in both neritic and oceanic ecosystems. The specific goals of the project are to a) determine the role of flow morphology in regulating particle capture within the houses of free-swimming appendicularians using micro-Particle Image Velocimetry, b) determine the effect of particle shape on retention efficiencies by appendicularians, and compare this effect between synthetic and biological particles, and c) quantify particle adhesion to the mucous filtration apparatus in order to determine if picoplankton cell surface properties influence retention efficiencies by mucous-net filter-feeders.

海洋的表面以微观动植物为主导，称为皮普兰克顿（Picoplankton），它们位于海洋食品网的底部。果冻样动物称为阑尾主义者，专门使用用粘液制成的网滤网过滤大量水来喂养这些微型生物。过去，人们认为阑尾主义者吃了任何通过粘液网的东西，但是新工作表明喂食可能具有选择性。海洋中最丰富的微生物（称为SAR 11）似乎逃避了阑尾，同时捕获了相似的光合微生物。 在这项研究中，将在美国俄勒冈州和法国维尔弗兰奇 - 塞尔 - 梅尔（Villefranche-Sur-Mer）进行一系列实验室和现场实验，以发现选择性的机制。该研究将测试粒子形状（例如球形与椭圆形），颗粒对粘液网的粘附特性以及流体动力学的作用。它将重点放在大都会的阑尾oikopleura dioica，这是皮科普兰克顿的重要放牧者。结果对于理解粘液 - 网络过滤器馈线在塑造海洋微生物群落的结构以及生物地球化学循环中的作用将很重要。该项目将支持一名早期职业教师，将为一名博士生和两名本科生提供培训和指导，涉及与法国和以色列的科学家合作，并将通过在Hatfield Marine Science Visitor Center和Charleston Marine Marine Life Center展示的展览和图像来吸引公众。 皮科普兰顿（Picoplankton）的密度高达每毫升一百万，并在数值上占据了上海猎物田。由于阑尾主义者通过其高过滤率和粘液骨料的产生影响Pico-和纳米颗粒通量，因此选择性放牧将对微生物环动力学和垂直通量产生重要的影响。因此，这项工作将提供有关上海中细菌群社区结构的机制的见解，并增强对NELITIC和OCEANIC生态系统中微生物 - 米塔唑食品互动的了解。 The specific goals of the project are to a) determine the role of flow morphology in regulating particle capture within the houses of free-swimming appendicularians using micro-Particle Image Velocimetry, b) determine the effect of particle shape on retention efficiencies by appendicularians, and compare this effect between synthetic and biological particles, and c) quantify particle adhesion to the mucous filtration apparatus in order to determine if粘液细胞表面特性会影响粘液 - 网络滤清器的保留效率。