Collaborative Research: Numerical Study of the Unsteady Feeding Currents in Calanoid Copepods

合作研究：桡足类不稳定进食流的数值研究

• 批准号: 0352284
• 负责人: Houshuo Jiang
• 金额: $ 19.29万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0352284&HistoricalAwards=false
• 关键词: Collaborative; Research; Numerical; Study; Unsteady

Numerical Study of the Unsteady Feeding Current in Calanoid Copepods This research project will address the question, "Why are there two temporal types of generating feeding currents among herbivorous calanoid copepods"? That is, why do animals show an on/off pattern, creating an unsteady flow, when they have to overcome the inertia of the surrounding water every time they start moving? The investigators will first directly observe feeding animals in situ. Then, they will observe them in 3D in the laboratory to define (1) the structures of the feeding currents, and (2), the temporal patterns under different food regimes. The database, which includes the shapes and sizes of the animals observed, will be used for simulations using computational fluid dynamics (CFD). The research team consists of an applied mathematician/environmental fluid dynamicist (Jiang, WHOI), a biological oceanographer (Paffenhofer, SKIO), and two experimental marine biologists (Strickler and Janssen, UWM). Experiments will be conducted during a two-week stay at the Wrigley Marine Science Center where we will observe Calanus pacificus and Rhincalanus nasutus in situ and in the laboratory. The results will be data on the frequencies of switching the feeding current on/off, and on the structures and temporal changes of the water flow around the animals. The investigators will also study the activity patterns of calanoid copepods from the ocean off Savannah, GA, under different food densities. All the data sets generated will be constantly used to design the simulations in CFD at WHOI. The investigators expect to find evidence that there exist different survival strategies among calanoid copepods living in nutritionally dilute environments. The strategy to alternate the generation of a feeding current may be based on a compromise between low excess weight, large body size, and low food concentrations. This would contrast to the strategy of high excess weight, constant feeding current, large sensing range, and moderate food density. Intellectual Merits Planktonic copepods live in environments of varying and often severely limiting food abundances. So far few if any studies have addressed the adaptations of copepod behavioral repertoires to this diminished food availability. This study is designed to improve our understanding of copepod feeding behavior by studying empirically free-swimming calanoids, which produce unsteady on/off feeding currents of different kinds, and then compare the newly gained results with our knowledge to date about the steady feeding currents. Broader Impact The project will support the research efforts of a young, physically oriented scientist in a well-integrated interdisciplinary study with three accomplished senior biological ocean scientists. The PIs well-visited web sites on zooplankton ecology, marine and fresh-water, will serve to stimulate young persons to pursue the natural sciences. The investigators will disseminate the results in the scientific literature. Two undergraduate students will be working at Skidaway with G. -A. Paffenhofer and will interact with the team of PIs during the course of the project. .

桡足类不稳定摄食电流的数值研究本研究项目将解决“为什么草食性桡足类有两种产生摄食电流的时间类型”的问题？ 也就是说，为什么动物每次开始移动时都必须克服周围水的惯性，从而表现出开/关模式，从而产生不稳定的流动？研究人员将首先在现场直接观察喂养动物。然后，他们将在实验室中以 3D 方式观察它们，以确定 (1) 进食电流的结构，以及 (2) 不同食物状态下的时间模式。该数据库包含观察到的动物的形状和大小，将用于使用计算流体动力学（CFD）进行模拟。 该研究团队由一名应用数学家/环境流体动力学家（Jiang，WHOI）、一名生物海洋学家（Paffenhofer，SKIO）和两名实验海洋生物学家（Strickler 和 Janssen，UWM）组成。实验将在箭牌海洋科学中心进行为期两周的停留，我们将在现场和实验室观察太平洋哲水蚤和鼻水哲藻。结果将是有关切换喂食电流的频率以及动物周围水流的结构和时间变化的数据。研究人员还将研究佐治亚州萨凡纳附近海域的桡足类动物在不同食物密度下的活动模式。生成的所有数据集将不断用于设计 WHOI 的 CFD 模拟。研究人员希望找到证据，证明生活在营养稀薄环境中的桡足类动物存在不同的生存策略。交替产生喂养电流的策略可以基于低超重、大体型和低食物浓度之间的折衷。这与高超重、恒定喂食电流、大感应范围和中等食物密度的策略形成对比。智力优点浮游桡足类生活在变化多端且往往严重限制食物丰度的环境中。到目前为止，很少有研究涉及桡足类行为库对食物供应减少的适应。本研究旨在通过实证研究自由游动的类足类动物（产生不同种类的不稳定开/关摄食电流）来提高我们对桡足类摄食行为的理解，然后将新获得的结果与我们迄今为止对稳定摄食电流的了解进行比较。更广泛的影响 该项目将支持一名年轻的、以物理为导向的科学家与三名卓有成就的高级生物海洋科学家进行良好整合的跨学科研究的研究工作。 PI关于浮游动物生态学、海洋和淡水的访问量很高的网站将有助于激励年轻人追求自然科学。 研究人员将在科学文献中传播研究结果。两名本科生将与 G. -A. 一起在 Skidaway 工作。 Paffenhofer 将在项目过程中与 PI 团队进行互动。 。