Collaborative Research: Prediction of Medusan Predatory Roles Based on Quantitative Studies of Animal-Fluid Interactions

一些研究发现，水母捕食在各种海洋浮游生物群落中起着主导作用，但控制水母猎物选择和摄食率的变量仍然存在争议。缺乏共识的一个可能的原因是，没有一个强有力的机械理解水母捕食，而不是一个单一的统一类型，水母是一个不同的系统发育，形态和功能阵列的捕食者的机械差异必须了解现实的捕食者模型可以构建之前。本研究将探讨的假设，功能的替代品的多样性受到限制的两个主要的机械解决方案水母运动：喷射和划船推进。研究人员认为，这些推进类型是理解捕食模式的关键，因为推进模式与觅食模式直接相关。然而，这提出了一个重大的挑战，因为只有喷气推进已定量描述水母。相比之下，所有记录在案的例子，浮游常设股票限制的水母涉及划船推进，巡航水母饲料的流体夹带的猎物在游泳。研究人员认为，流体与水母猎物捕获表面的相互作用的量化是预测水母猎物选择和摄食率的现实模型构建的必要先决条件。该项目的第一个目标是定量描述赛艇和喷射推进的流体动力学特征。这将涉及一个跨学科的比较研究的主要水母谱系的代表性成员使用DPIV测量自由游泳的动物和新开发的方法，这些定量流动可视化的分析和解释。根据这些结果，研究人员将推导出适用于主要水母谱系的适当流体动力学模型。第二个主要目标是定量描述流体流动和捕获表面之间的相互作用，最具生态影响力的水母谱系-划船推进，巡航觅食。这一组的成员包括各种血统，捕捉猎物的上游（如Narcomedusae，Coronalus）或下游（如Leptomedusae，Semastomeae，Racostomeae）组件周围的游泳钟流。这项研究将详细说明过去的流体流速捕获表面，并将作为水动力学为基础的清除率估计的水母predation.Intellectual优点的拟议活动：水母捕食影响所有的浮游生物群，和发展的水动力学为基础的理解水母捕食将有可能广泛应用于其他浮游生物类群的研究。此外，这些信息将为动物游泳和综合海洋动物行为领域提供新的概念见解。从这个角度来看，本研究直接解决了理解影响生物多样性的因素及其在海洋系统中的生态后果的问题，NSF的生物海洋学部门强调的一个特定主题。此外，阐明海洋运动的设计原则可以补充现有的研究水下航行器设计的启发，鱼swimming.Broader影响的拟议活动：学生，主要是本科生，将参与各个方面的拟议研究和调查人员将参加计划，旨在指导这些机会的培训和指导对代表性不足的本科生。参与这项合作的两名主要研究人员主要来自本科院校，一名主要来自研究生院校。代表性不足的本科生的参与将通过在加州理工学院旨在提供研究机会，以少数民族学生从全国各地的其他校园既定计划鼓励。加州理工学院的研究员也将继续担任加州理工学院新生暑期研究所（FSI）研究计划的协调员。这项为期四周的年度计划于2001年启动，以应对来自代表性不足的群体的学生人数不成比例地少，参加校园内的研究活动。此外，他们将利用他们与参与公众教育的媒体的联系，传达我们关于水母形式和功能的新发现。最后，将开发一个在线教程，将新的实验DPIV方法传播给其他研究小组，调查水生生物力学和海洋生态学的各种主题。

Several studies have found that medusan predation plays a dominant role in a variety of marine planktonic communities, but the variables controlling medusan prey selection and ingestion rates remain contentious. A possible reason for this lack of consensus is that there is not a strong mechanistic understanding of medusan predation and, rather than a single uniform type, medusae are a diverse phylogenetic, morphological and functional array of predators whose mechanical differences must be understood before realistic predator models can be constructed. This study will examine the hypothesis that the diversity of functional alternatives are constrained to two major mechanical solutions for medusan motility: jetting and rowing propulsion. The investigators argue that these propulsion types are the key to understanding predation patterns because propulsive mode is directly related to foraging mode. However, this presents a major challenge because only jet propulsion has been quantitatively described in medusae. In contrast, all of the documented examples of planktonic standing stock limitation by medusae involve rowing-propelled, cruising medusae that feed by fluid entrainment of prey during swimming. The investigators contend that quantification of fluid interactions with medusan prey capture surfaces is a necessary prerequisite to the construction of realistic models predicting medusan prey selection and ingestion rates. The first goal of the project is to quantitatively delineate hydrodynamic characteristics of rowing and jetting propulsion. This will involve an interdisciplinary comparative study of representative members of major medusan lineages using DPIV measurements of free-swimming animals and newly developed methods for the analysis and interpretation of these quantitative flow visualizations. From these results, the investigators will deduce appropriate hydrodynamic models for application to major medusan lineages. The second major goal is to quantitatively describe the interactions between fluid flows and capture surfaces of the most ecologically influential medusan lineages - the rowing-propelled, cruising foragers. Members of this group include various lineages that capture prey in either the upstream (e.g. Narcomedusae, Coronatae) or downstream (e.g. Leptomedusae, Semastomeae, Rhizostomeae) components of flow around the swimming bell. This research will detail the fluid flow rates past capture surfaces and will serve as the basis for hydrodynamically-based clearance rate estimates of medusan predation.Intellectual Merit of the Proposed Activity: Medusan predation affects all planktonic groups, and development of a hydrodynamically based understanding of medusan predation will have potentially wide application to studies of other planktonic taxa. Additionally, this information will contribute novel conceptual insights to the fields of animal swimming and integrated marine animal behavior. From this perspective, this study directly addresses the issue of understanding factors influencing biological diversity and its ecological consequences in marine systems, a specific theme emphasized by NSF's Biological Oceanography division. Furthermore, the elucidation of governing design principles in marine locomotion can complement existing studies of underwater vehicle design inspired by fish swimming.Broader impacts of the Proposed Activity: Students, primarily undergraduates, will participate in every aspect of the proposed research and the investigators will participate in programs designed to direct these opportunities for training and mentorship toward underrepresented undergraduate students. Two of the principal investigators participating in this collaboration are from primarily undergraduate institutions and one is from a primarily graduate institution. The participation of underrepresented undergraduate students will be encouraged through established programs at Caltech aimed at providing research opportunities to minority students from other campuses across the country. The Caltech investigator will also continue in his role as Coordinator of the Freshmen Summer Institute (FSI) Research Program at Caltech. This annual, four-week program was initiated in 2001 in response to the disproportionately low number of students from underrepresented groups participating in research activities on campus. In addition, they will use their contacts with media involved in education of the general public to communicate our new findings about medusan form and function. Finally, an online tutorial will be developed to disseminate the new experimental DPIV methods to other research groups investigating various topics in aquatic biomechanics and marine ecology.