Functional Morphology of Aquatic Locomotion in Fishes: Function of Median Fins

几百年来，研究动物如何移动并产生对抗环境的力量一直是生物学家感兴趣的话题。引起这种兴趣的一个关键原因是，除非能够测量肌肉收缩的效果，否则很难理解肌肉和骨骼是如何起作用引起运动的。这表现为施加在环境上的力。然而，尽管测量力的能力很重要，但由于我们无法直接测量动物在空气或水中运动时的力，因此对许多运动生物的肌肉收缩效果的分析仍然是推断性的。在陆地上，动物对地面施加力，这些力可以直接测量。但这种直接测量在流体中是不可能的，生物学家也缺乏进行这种测量的方法。这项提议将应用工程师们最近开发的一项技术的结果，该技术被称为数字粒子图像测速（DPIV），它可以直接量化运动流体的流动，并计算生物施加在流体上的力。这项技术将应用于脊椎动物生物学中的一个经典问题：鱼类鳍的功能和进化。由于中鳍在早期脊椎动物化石中的突出地位，它们在运动中的重要性，以及鱼类中中鳍形状的多样性，几乎每一本比较解剖学、古生物学和功能形态学的教科书都讨论了鳍的进化。本研究将使用DPIV直接可视化鱼鳍上的水流速度，并计算运动产生的力。PI将使用DPIV结合三维鳍运动分析和鳍肌肉产生的电活动记录来测试关于鱼类如何在水中产生力的假设。提出了本研究的初步数据，证明了应用该技术的可行性，初步结果显示了本研究将产生的数据的特征。本研究为水生运动的实验研究提供了一种强有力的新技术，通过首次直接量化鳍周围和鳍后的流动，本研究将为水生推进机制提供新的数据，并有助于澄清脊椎动物功能形态学中的一个经典问题。

Lauder 9807012 The study of how animals move and generate force against the environment has been a topic of interest to biologists for hundreds of years. One key reason for this interest is that it is very difficult to understand how muscles and bones function to cause movement unless one is able to measure the effect of muscle contraction. This appears as force exerted on the environment. However, despite the importance of the ability to measure forces, analysis of the effect of muscle contraction has remained inferential for many moving organisms because of our inability to directly measure force when animals move in air or water. On land, animals exert force on the ground and these forces can be measured directly. But such direct measurements are not possible in fluids, and biologists have lacked a means of making such measurements. This proposal will apply the results of a technique developed recently by engineers called Digital Particle Image Velocimetry (DPIV) which allows direct quantification of flow in moving fluids and the calculation of the force exerted on the fluid by organisms. This technique will be applied to a classical problem in vertebrate biology: the function and evolution of fins in fishes. Because of the prominence of median fins in early vertebrate fossils, their importance in locomotion, and the diversity of median fin shapes in fishes, the evolution of fins has been discussed in virtually every textbook of comparative anatomy, paleontology, and functional morphology. This study will use DPIV to visualize directly water velocity over fins of fishes and to calculate the forces that result from movement. The PI will use DPIV in conjunction with analysis of three-dimensional fin movements and recordings of the electrical activity generated by fin muscles to test hypotheses about how fishes generate force on the water. Preliminary data for this study are presented which demonstrate feasibility of applying this technique and init ial results show the character of the data that would result from this research. This proposal will introduce a powerful new technique for the experimental study of aquatic locomotion, and by directly quantifying for the first time flow around and behind fins, this study will provide novel data on mechanisms of aquatic propulsion and contribute to clarifying a classic issue in vertebrate functional morphology.