SGER: Biomechanics of Suction Feeding in Teleost Fishes

皮特·C·温赖特、安吉拉·切尔和哈里·A·德怀尔加州大学戴维斯分校这项研究将研究水生吸食的机制，这是脊椎动物最广泛使用的水生猎物捕获方法。吸食在每个主要的四足类中至少有一些成员被发现，并且是硬骨鱼使用的主要捕食机制。这种行为涉及到口腔和口腔的爆炸性扩张，以加速水和猎物进入口腔。这项研究的目的是使用一种新的方法来可视化和测量鱼类在吸食过程中产生的水流。由于生物系统中水流的可视化和测量相当困难，目前缺乏关于吸力喂食流量的数据。这些流动是这项研究计划的重点，因为它们对猎物施加力量，将它们输送到捕食者手中，并决定吸入喂食器的成功。了解吸食器产生的水流的空间和时间模式，以及它们如何对猎物施力，是理解吸食器的机制及其更广泛的生物学的关键。数字粒子图像测速技术(DPIV)是一种能够可视化和量化水运动的技术，将被开发为一种工具，用于在重点物种蓝鳍太阳鱼(Lepomis Macchirus)的实验中研究吸食。DPIV将与抽吸压力和头骨运动的超声波测量结合使用，以解决三个问题。首先，在吸食过程中，施加在猎物身上的力有多大？阻力和加速度反作用力在产生这些力中的相对重要性是什么？计算流体力学模型的初步计算表明，加速度反作用力可能会超过更常见的阻力。加速度反作用力是一种以前被忽略的力，由变速流动产生。证明加速反应的重要作用将极大地改变猎物所经历的力的图景，并可能有助于解释吸食的爆炸性，吸食是脊椎动物中所见的最快的取食行为之一。其次，将确定在捕获猎物过程中产生的吸力压力和流速之间的定量关系。这一关系将被用来检验被广泛接受的假设，即峰值吸力流量与峰值吸力压力成正比。第三，测量吸力喂入过程中流速的时间和空间分布。这将建立捕食者-猎物相互作用的关键区域和时间过程，并为未来的比较研究提供基准。本研究代表了DPIV技术在活体水生生物研究中的一种新应用，该研究以前未被应用于摄食行为。开发这种方法带来了与动物训练和靠近移动的颌骨结构的流动可视化相关的重大挑战。尝试建立这种新的吸力进料研究方法的风险是合理的，因为流动数据的基本性质有助于理解吸力进料机理。测量流速的空间和时间模式是推断吸力和吸力进给性能的关键。这一研究项目将建立一种研究吸食的新技术，并将有助于更深入地了解脊椎动物进化的重要一步。更多关于吸食的知识将拓宽我们对硬骨鱼头骨设计和生物力学之间关系的洞察力。该项目的更广泛影响包括非定常流动在外科吸引器中的应用。这项研究还将为连接工程学和生物学学科的博士后研究员提供培训。

SGER: Biomechanics of suction feeding in teleost fishesPeter C. Wainwright, Angela Cheer, and Harry A. DwyerUniversity of California, DavisThis research will investigate the mechanics of aquatic suction feeding, the most widespread method of aquatic prey capture used by vertebrate animals. Suction feeding is found in at least some members of every major group of tetrapods, and is the principal prey capture mechanism used by teleost fishes. The behavior involves the explosive expansion of the mouth and oral cavity to accelerate water and prey into the mouth. The aim of this research is to use a new method to visualize and measure the water flows generated by fishes during suction feeding. The lack of existing data on suction feeding flows is due to the considerable difficulty of visualizing and measuring water flow in biological systems. These flows are the focus of this research proposal because they exert forces on prey, transporting them to the predator and determine the success of suction feeders. Understanding the spatial and temporal pattern of water flow generated by suction feeders and how they exert forces on prey is the key to understanding the mechanics of suction feeding and its broader biology. Digital Particle Image Velocimetry (DPIV), a technology that permits the visualization and quantification of water motion, will be developed as a tool for studying suction feeding in experiments with a focal species, the bluegill sunfish, Lepomis macrochirus. DPIV will be used in conjunction with measurements of suction pressure and ultrasound of skull movements to address three issues. First, what are the magnitudes of the forces exerted on prey during suction feeding and what is the relative importance of drag and the acceleration reaction in generating these forces? Preliminary calculations with a computational fluid dynamics model indicate that acceleration reaction, a previously ignored force that is generated by flows of changing velocity, may outpace the more familiar drag forces. Demonstrating an important role for acceleration reaction would greatly alter the picture of forces that are experienced by prey, and may help to explain the explosive nature of suction feeding, one of the fastest feeding behaviors seen among vertebrate animals. Second, the quantitative relationship between suction pressure and the flow velocities that are generated during prey capture will be determined. This relationship will be used to test the widely held assumption that peak suction flows are proportional to peak suction pressure. Third, the temporal and spatial patterns of flow velocity during suction feeding will be measured. This will establish the critical area and time-course of predator-prey interactions and provide a benchmark for future comparative studies.This research represents a novel application of DPIV technology in studies with live aquatic organisms that has not previously been applied to feeding behavior. Developing this method presents significant challenges associated with animal training and visualization of flow close to moving jaw structures. The risk of attempting to establish this new method for research on suction feeding is justified because of the fundamental nature of flow data to understanding suction feeding mechanics. Measuring the spatial and temporal pattern of flow velocity is a key to inferring forces and hence suction feeding performance. This research project will establish a new technology for studying suction feeding and will contribute to a deeper understanding of a major step in vertebrate evolution. A greater knowledge of suction feeding will broaden our insights into the relationship between skull design and biomechanics in teleost fishes. Broader impacts of this project include the application of unsteady flows in surgical suction devices. This research will also provide training for a postdoctoral researcher who is bridging engineering and biology disciplines.