Experimental Hydrodynamics and Evolution: function of median fins in ray-finned fishes

实验流体动力学和进化：射线鳍鱼中鳍的功能

• 批准号: 0316675
• 负责人: George Lauder
• 金额: $ 42.57万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0316675&HistoricalAwards=false
• 关键词: Experimental; Hydrodynamics; Evolution; function; median

Organisms that live in the water represent a substantial fraction of life's diversity, and understanding how animals move through water, exert forces on their environment, and control their body position in a turbulent environment is critical to developing insights into the diversity of aquatic life. However, attempts to study this question over the past 20 years have met with many difficulties. Chief among these has been the considerable technical difficulty of quantifying the forces exerted by the movement of organisms on the water. On land such measurements are technically easy (stepping on a scale, for example, gives a force measurement of the body on the ground), but our inability to quantify forces exerted by organisms in the water has made it very difficult to understand the functional significance of different body and fin shapes.This study adopts from the field of engineering a new flow visualization technique called Digital Particle Image Velocimetry (DPIV) and modifies it to study fish body and fin motion. This technique provides, for the first time, a means of experimentally quantifying water movement in the wake of freely swimming fishes, and calculating the magnitudes and directions of forces exerted on the water by fins and the body of freely-moving aquatic organisms. Progress on previous NSF grants has demonstrated the ability of DPIV to provide data critical to understanding mechanisms of aquatic locomotion in organisms, and has shown how using this new approach to measuring the motion of water leads to previously unexpected insights into the diversity of aquatic organisms. The general objectives of this research are to study the hydrodynamic function of fins in fishes, focusing on the dorsal and caudal fins in sunfish, trout, and sturgeon with the aim of testing several long-standing hypotheses in the literature regarding the mechanisms by which these fins generate force and allow fishes to maneuver and position themselves in the water. Of special interest is the hypothesis of "wake interception" : that fishes can enhance the force generated by their tail fin by having the tail intercept the hydrodynamic wake shed by the dorsal fin. If this hypothesis is corroborated, it will represent an important new general mechanism by which both organisms and man-made submersibles could increase their propulsive efficiency. This research project contributes to advanced training of undergraduates in new approaches and technologies for the study of animal biomechanics and evolution through individual student research projects in an advanced undergraduate course co-taught by the Principal Investigator (PI), the interdisciplinary training of biology graduate students in engineering approaches to the study of organismal function, and post-doctoral training for the next generation of academic faculty. The research proposed here will have increased breadth of impact through a broad new training program in biomechanics at Harvard University which integrates biomechanics graduate training in biology, chemistry, physics, and engineering. The PI is one of the faculty on this grant, and the research proposed will serve as projects for students undertaking mandatory rotations, thus introducing a wide diversity of chemistry, physics and engineering graduate students to concepts and approaches in organismic functional biology that they would not otherwise be exposed to.

生活在水中的生物代表了生命多样性的很大一部分，了解动物如何在水中移动，对环境施加力，并在动荡的环境中控制自己的身体位置，对于深入了解水生生物的多样性至关重要。 然而，过去20年来研究这一问题的尝试遇到了许多困难。 其中最主要的是，要量化生物体在水面上运动所施加的力存在相当大的技术困难。在陆地上，这样的测量在技术上是容易的（例如，踩在秤上，可以测量身体在地面上的力），但是我们无法量化生物在水中施加的力，这使得我们很难理解不同的身体和鳍形状的功能意义。本研究采用了工程领域的一种新的流动可视化技术，称为数字粒子图像速度计（DPIV）。并将其修改为研究鱼体和鳍的运动。 这项技术首次提供了一种方法，通过实验量化自由游动的鱼类尾流中的水运动，并计算自由移动的水生生物的鳍和身体对水施加的力的大小和方向。 先前NSF赠款的进展已经证明了DPIV提供对理解生物体中水生运动机制至关重要的数据的能力，并表明了如何使用这种新方法来测量水的运动，从而对水生生物的多样性产生了以前意想不到的见解。 本研究的总体目标是研究鱼类鳍的流体动力学功能，重点是太阳鱼，鳟鱼和鲟鱼的背鳍和尾鳍，目的是测试文献中的几个长期存在的假设，这些鳍产生力的机制，并允许鱼类在水中操纵和定位。 特别令人感兴趣的是“尾流拦截”的假设：鱼类可以通过尾部拦截背鳍脱落的水动力尾流来增强尾鳍产生的力。 如果这一假设得到证实，它将代表一个重要的新的一般机制，生物和人造潜水器可以提高其推进效率。 该研究项目有助于通过主要研究者（PI）共同教授的高级本科课程中的个别学生研究项目，对本科生进行动物生物力学和进化研究的新方法和技术的高级培训，生物学研究生的跨学科培训，以及为下一代学术人员提供博士后培训。这里提出的研究将通过哈佛大学生物力学的一个广泛的新培训计划增加影响的广度，该计划将生物力学研究生培训整合在生物学，化学，物理学和工程学中。PI是该补助金的教师之一，所提出的研究将作为学生进行强制性轮换的项目，从而为化学，物理和工程研究生介绍各种各样的概念和方法，否则他们不会接触到器官功能生物学。