Collaborative Research: IOS:RUI: Hydrodynamic consequences of spines on zooplankton: Functional morphology of horns and tails on barnacle nauplii

浮游动物是随洋流漂流的小动物，是海洋食物链中的关键环节。许多不同类型的浮游动物都有细长的刺、角或毛。这些结构被认为是捕食者的威慑或感觉触角。这个项目考察了脊椎可能影响的其他重要的生态功能：摄食、游泳、下沉和从表面移位。这些功能取决于动物如何与周围的水互动。这项研究调查了刺是如何改变周围水的运动的，以及在不同种类的藤壶幼体的早期发育过程中，水的运动是如何变化的。藤壶是甲壳类动物的一种，包括商业上重要的螃蟹、虾和龙虾。由于所有甲壳类动物都有无节幼体阶段，这项研究将阐明这种常见的身体形态是如何运作的，提供关于不同行为和身体形状之间的功能权衡的信息。这个项目是一所小型文科本科学院和一所大型研究型大学的合作项目，汇集了来自两个学院的学生和教职员工，以开展研究并培训本科生。此外，这个项目跨越了生物学和工程学之间的学科界限，因此来自不同领域的学生将学习如何交流和合作。从这项研究中发现的原理可以启发水生微型机器人的生物灵感设计。设计的实验类型也将用于开发新的科学课程。各式各样的浮游动物都有脊椎，但其功能却鲜为人知。这项对不同种类藤壶幼虫的水动力学研究将确定(1)刺的存在、位置和形态对水动力和扭矩的功能影响；(2)刺和附肢运动学对所产生的力和力矩以及对游泳、下沉和摄食性能的功能影响；(3)从浮游无节幼体到定居鲤鱼形态的身体设计变化的水动力学结果。利用显微摄像技术和高速粒子图像测速仪对形态和生态各异的幼虫的运动学和流场进行了测量。这种对活体的比较研究与使用动态缩放物理模型的实验相结合，以确定特定特征控制幼虫受到的力和扭矩以及周围流场的机制。物理模型允许参数--脊柱的大小和形状、身体的大小和形状、肢体形态和运动学--以活体生物不可能实现的方式进行变化。除了阐明关于浮游动物的大小和速度范围--中间雷诺数的范围--的脊椎的流体动力学后果的一般原理之外，该项目还将促进人们对生态功能之间的权衡如何施加生物力学约束的理解，这些约束可以塑造形式的演变。PUI学院和R1大学之间的合作将两所大学的研究和本科教育结合在一起。这种以问题为导向、以经验为基础的学习方法涉及来自物理和生物科学的本科生研究团队，以发展他们在跨学科合作方面的技能。将开发新的跨学科课程材料，提供丰富的上下文模块，用于教授量化技能。该奖项反映了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。

Zooplankton, small animals that drift with ocean currents, are critical links in marine food webs. Many different types of zooplankton have elongated spines, horns, or hairs. These structures are thought of as predator deterrents or sensory antennae. This project examines other ecologically important functions that spines might impact: feeding, swimming, sinking, and dislodgement from surfaces. These functions depend on how animals interact with the water around them. This study investigates how spines work to alter the movement of the surrounding water and how that water movement varies in the early development of the “nauplius” larval stage of different species of barnacles. Barnacles are a type of crustacean, a group that includes the commercially important crabs, shrimp, and lobsters. Since all crustaceans have a nauplius larval stage, this research will shed light on how this common body form operates, providing information about functional tradeoffs between different behaviors and body shapes. This project -- a collaboration between a small, liberal arts undergraduate college and a big research university -- brings together students and faculty from both to conduct the research and to train undergraduates. In addition, this project crosses disciplinary boundaries between biology and engineering, so students from different fields will learn how to communicate and collaborate. Principles discovered from this study can inform bio-inspired design of aquatic microrobots. The types of experiments designed will also be used to develop new science curricula. Diverse zooplankters bear spines with functions that are poorly understood. This study of the hydrodynamics of different species of barnacle larvae will determine (1) functional consequences of the presence, location, and morphology of spines on hydrodynamic forces and torques; (2) functional consequences of spines and appendage kinematics on the forces and torques generated, and on swimming, sinking, and feeding performance; and (3) hydrodynamic consequences of the change in body design from the planktonic nauplius to the settling cyprid form. Kinematics and flow fields of larvae with distinctive morphologies and ecology are measured using micro-videography and high-speed particle image velocimetry. This comparative study on live organisms is coupled with experiments using dynamically scaled physical models to determine mechanisms by which specific features control forces and torques on, and flow fields around, larvae. Physical models allow parameters – spine size and shape; body size and shape; limb morphology; and kinematics -- to be varied in ways not possible with living organisms. In addition to elucidating general principles about the hydrodynamic consequences of spines at the poorly understood size and speed range of zooplankton – the domain of intermediate Reynolds numbers -- the project will advance understanding of how tradeoffs between ecological functions impose biomechanical constraints that can shape the evolution of form. Collaboration between a PUI college and R1 university integrates research and undergraduate education at both. The question-driven, experience-based learning approach involves research teams of undergraduates from physical and biological sciences to develop their skills at interdisciplinary collaboration. Novel interdisciplinary course materials will be developed with context-rich modules for teaching quantitative skills.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.