Schooling through Vortex Streets; A Biological and Computational Approach to Understanding Collective Behavior in Wild Fish

几个世纪以来，成群结队的动物操纵和导航的能力一直让人类着迷。在经济和生态上最重要的鱼类是群居鱼类，它们成群结队地游动，在汹涌的洋流中迁徙数百英里。在日常生死攸关的场景中，一所学校如何感知自己的湍急尾流和不可预测的洋流，并在其中移动，对于它的成功至关重要。在这种情况下，个体必须迅速而有凝聚力地从大型、快速攻击的捕食者的嘴巴中逃脱。因为邻近的领域，如自主群体机器人，是基于生物鱼群的集体行为并受到其启发，因此迫切需要了解复杂的尾迹如何促进或破坏鱼群中有组织的、有凝聚力的运动。对这一现象的洞察掌握着解开未知机制的关键，这些机制可以推动集体行为、神经科学、进化、运动生态学、机器人学和流体动力学等领域的发展。学校教育背后的流体力学机制在很大程度上仍然是推测的，因为缺乏一个用野生、行为正常的动物进行实验的理论框架。为了迎接这一挑战，该项目将利用计算流体力学建模和活鱼实验来研究圆柱体阵列下游的涡街相互作用。该项目的总体目标是确定相互作用的涡街影响鱼群形成模式的基本机制。该研究项目将通过为本科生和公众提供真实的研究体验，扩大代表不足的群体在STEM领域的参与。这包括惠特尼海洋生物科学实验室的长期运行的NSF REU计划和K-9推广计划，在社交媒体上的存在(超过1万YouTube订阅者)，以及一本正在撰写的科普书籍(普林斯顿大学出版社)。PI将结合计算流体动力学(CFD)建模、机器学习运动跟踪算法、生物生物力学和实验感觉神经科学来研究复杂的水动力环境如何影响鱼群的集体行为，目标如下。目标1：确定产生最大程度吸引鱼类的涡流尾流的气缸布置，以及次优控制配置。假设存在使涡街的连贯性最大化的最优排列，并且它由两个方向的每个方向都具有恒定间距的结构化阵列组成。目的2：揭示实验圆柱尾迹后个体和集体鱼群的分布模式。这里的假设是，鱼的行为取决于圆柱体的分布和相关的湍流。目的3：研究鱼类如何保持一致的鱼群形态的感觉生物学。PI假设，面对复杂的流动，鱼群优先考虑视觉而不是流动感觉。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The ability of swarming animals to maneuver and navigate has fascinated humans for centuries. The most economically and ecologically important fishes are schooling fishes that swim together in the millions and migrate hundreds of miles through turbulent ocean currents. How a school senses and moves through its own turbulent wake and unpredictable ocean currents is vital to its success in daily life-or-death scenarios, where individuals must quickly and cohesively maneuver out of the jaws of large, fast-attacking predators. Because adjacent fields such as autonomous swarm robotics are based on and inspired by the collective behavior of biological fish schools, there is a critical need to understand how complex wakes can facilitate or disrupt organized, cohesive motion in schooling fishes. Insight into this phenomenon holds the key to unlocking unknown mechanisms that could advance the fields of collective behavior, neuroscience, evolution, movement ecology, robotics and fluid dynamics. The hydrodynamic mechanisms underlying schooling remain largely speculative due to the lack of a theoretical framework with which to experiment with wild, behaving animals. To meet this challenge, this project will examine the vortex street interactions downstream of arrays of cylinders by leveraging both computational fluid dynamics modeling and live fish experiments. The overall objective of the project is to define the fundamental mechanisms with which interacting vortex streets influence the patterns of formation in schooling fishes. The research project will broaden participation of underrepresented groups in STEM fields by providing an authentic research experience for undergraduate students and the public. This includes the long-running NSF REU program and K-9 outreach program at the Whitney Lab for Marine Bioscience, an established social media presence (over 10k YouTube subscribers), and a popular science book currently being written (Princeton University Press).The PI will combine computational fluid dynamic (CFD) modeling, machine-learning motion-tracking algorithms, organismal biomechanics, and experimental sensory neuroscience to examine how complex hydrodynamic environments impact the collective behavior of schooling fishes with the following aims. Aim 1: Determine the arrangement of cylinders that generates vortex wakes that maximize attraction to fish, as well as sub-optimal control configurations. The hypothesis is that an optimal arrangement maximizing the coherency of the vortex street exists and it consists of a structured array with a constant spacing for each of the two directions. Aim 2: Reveal distribution patterns of schooling fishes, both individually and collectively, behind experimental cylinder wakes. Here the hypothesis is that fish behavior depends on the cylinder distribution and relevant turbulent flow. Aim 3: Investigate the sensory biology of how fish remain in coherent schooling formations. The PI hypothesizes that faced with complex flows, schooling fish prioritize vision over flow sensing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.