Collaborative Research: Navigating through space in turbulence tubes: Copepod responses to Burgers' vortex

桡足类是海洋环境中无处不在的动物，在世界海洋的食物网中发挥着至关重要的作用。桡足类动物感知流体运动的能力为关键的生存策略提供了优势，如寻找食物、寻找配偶和躲避捕食者。这个项目将考察桡足类探测湍流的能力。在实验室水族馆中，类似湍流的流动将被模拟为一个小漩涡(即像龙卷风一样的漩涡运动)，并且将在漩涡内和漩涡周围观察到桡足类动物的游泳行为。目的是了解三种具有代表性的传感器阵列的三种桡足类感觉生态的变化，以更好地解释它们在海洋中对湍流条件的反应的时间和空间分布。该项目还有一个强有力的教育和外展计划。它将为工程、生物和计算科学等领域的研究生和本科生提供跨学科培训。此外，研究结果将为计划在当地高中和水族馆教育普通公众的外展工作提供背景。该项目将通过对三种桡足类动物及其周围的游泳进行详细的运动学分析来解构湍流-桡足类动物的相互作用。实验室实现了Burgers涡，它模拟了在尺度耗散范围内的原位湍流涡旋。其目的是验证这样一种假设，即桡足类动物Tcartia tonsa、Thema Longicornis和Calanus finmarchicus可以检测到与湍流中的漩涡相关的流体动力学信号，并通过游泳运动学的变化做出积极的反应。使用定制设计和校准的仪器，将在实验室中创建一个类似湍流的漩涡。通过在空间中保持湍流涡旋的稳定，摄像机将聚焦于该特征的一小部分区域，以记录相对于良好量化的流动特征的动物行为。这种方法的优点是消除了湍流的时变性和随机性，这使得这种机械性的理解变得如此具有挑战性。假说将解决关于游泳方式、Setal阵列结构以及化学和流体动力学线索的相互作用对湍流-桡足类相互作用的影响的问题。具体地说，研究人员将研究具有不同感觉结构和游泳方向的桡足类物种对稳定的明确实验室刺激的反应，以确定桡足类如何利用湍流特征的形状和方向。为这项工作选择的桡足类物种提供了一系列的感觉结构、游泳方向、大小和配偶跟踪能力。

Copepods are ubiquitous animals in marine environments and play a critically-important function in the food web of the world's oceans. The ability of a copepod to sense fluid motion provides an advantage for critical survival tactics such as finding food, finding mates, and avoiding predators. This project will examine the capability of copepods to detect turbulent flow. A turbulent-like flow will be mimicked in a laboratory aquarium as a small vortex (i.e., swirling motion like a tornado), and copepod swimming behavior will be observed in and around the vortex. The goal is to understand the variations in the sensory ecology of three species of copepods with three representative sensor arrays to better explain their temporal and spatial distribution in the ocean in response to turbulence conditions. The project also has a strong education and outreach plan. It will provide interdisciplinary training for graduate and undergraduate students in fields such as engineering, biology, and computational sciences. Further, research results will provide context for planned outreach efforts to educate the general public at local high schools and aquariums.The project will deconstruct the turbulence-copepod interaction by performing detailed kinematics analysis of swimming in three species of copepods in and around a laboratory realization of a Burgers' vortex that mimics in situ turbulent vortices in the dissipation range of scales. The goal is to test the hypothesis that the copepods Acartia tonsa, Temora longicornis, and Calanus finmarchicus detect hydrodynamic cues related to vortices in turbulent flows and actively respond via changes in swimming kinematics. Using a custom designed and calibrated apparatus, a turbulent-like vortex will be created in the laboratory. By holding the turbulent vortex stable in space, cameras will be focused on a small region of the feature to record the animal behavior relative to well-quantified flow characteristics. The approach has the advantage of eliminating the time-varying and stochastic nature of turbulent flows that make such mechanistic understanding so challenging to achieve. Hypotheses will address questions about the influence of swimming style, setal array architecture, and the interaction of chemical and hydrodynamical cues on the turbulence-copepod interaction. Specifically, the investigators will examine how copepod species with different sensory structures and swimming orientation respond to a stable well-defined laboratory stimulus to determine how copepods exploit the shape and orientation of turbulent features. The species of copepods chosen for this work provide a range of sensory architectures, swimming orientations, sizes, and mate tracking abilities.