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

桡足类动物在海洋环境中无处不在，在世界海洋的食物网中起着至关重要的作用。桡足类动物对流体运动的感知能力为寻找食物、寻找配偶和躲避捕食者等关键生存策略提供了优势。这个项目将检验桡足类动物探测湍流的能力。类似湍流的流动将在实验室水族箱中模拟成一个小漩涡（即，像龙卷风一样的漩涡运动），桡足动物的游泳行为将在漩涡内和周围被观察到。目的是通过三种具有代表性的传感器阵列来了解三种桡足类动物的感官生态变化，以更好地解释它们在湍流条件下在海洋中的时空分布。该项目还有一个强有力的教育和推广计划。它将为工程、生物学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公众的推广工作提供背景。该项目将解构湍流-桡足动物的相互作用，通过对三种桡足动物在实验室实现的汉堡涡旋及其周围进行详细的运动学分析，模拟尺度耗散范围内的原位湍流涡旋。目的是验证这样一种假设，即桡足动物Acartia tonsa、Temora longicornis和Calanus finmarchicus能够探测到湍流中与漩涡有关的流体动力学线索，并通过游动运动学的变化积极地做出反应。使用定制设计和校准的设备，将在实验室中创建类似湍流的漩涡。通过保持湍流涡旋在空间中的稳定，相机将聚焦在特征的一个小区域，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和随机特性，而这些特性使得这种机制的理解很难实现。假设将解决有关游泳方式、设置阵列结构以及化学和流体动力学线索对湍流-桡足动物相互作用的影响的问题。具体来说，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如何对稳定的明确定义的实验室刺激做出反应，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动物提供了一系列的感官结构、游泳方向、大小和配偶追踪能力。

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.