Fish Maneuverability: Factors Affecting Turning and Agility

9507197长久以来，鱼类的速度和机动性吸引了人类的想象力。大多数研究关注的是鱼类如何高速游泳和加速，但到目前为止，我们对物种之间差异的原因知之甚少。可操纵性可能提供了统一的解释，但实际上没有研究鱼的可操纵性，它对速度和加速度的影响，或鱼的身体和鳍的变化如何提高或限制可操纵性。本研究的目的就是为了填补这一空白。机动性包括两个组成部分：在小半径圆周内转弯的能力（转弯半径）和高速转弯的能力（敏捷性）。鱼使用不同的运动模式或步态来以不同的速度游泳。它们的主要步态是由中间鳍和成对鳍驱动的常规游泳，用身体和尾鳍巡航和冲刺，以及用身体和尾鳍快速加速。不同步态的机动性不同，实验将使用迷宫、圆形跑道和快速启动试验来测量每种步态的机动性。可操作性将通过对电影或录像的逐帧分析来衡量。将研究三种体型和鳍位置不同的鱼类。在障碍物周围进食和迷宫中运动时的机动性测量将决定形状如何影响运动性能（机动性）和中鳍和成对鳍游泳时的能量增益。在冲刺时，鱼会减速转弯。这与目前关于鱼类的理论相反，该理论可能基于次最大性能水平。对快速启动动作的分析将测试一个统一的模型，在这个模型中，整体性能取决于速度、转弯时机和转弯半径。这些变量决定了行为的一般模式，线性加速和减速模式的细节以及最终的逃逸轨迹。该研究将提供各种活动的可操作性的详细测量和统一的方法来研究游泳行为的种内和种间变化。由于可操作性可能制约生境选择，因此该研究将有助于解决水生生境恢复等问题。了解限制速度和机动性的因素将有助于在工业实践中最大限度地减少因夹带造成的鱼类损失。

9507197 The speed and maneuverability of fishes have long captured human imagination. Most research has been concerned with how fish swim at high speeds and accelerate at high rates, but as yet we have little understanding of the causes for differences between species. Maneuverability may provide the unifying explanation, yet there are virtually no studies on fish maneuverability, its effects on speed and acceleration, or how variability in fish body and fin form improves or restricts maneuverability. The purpose of the proposed research is to fill this gap. Maneuverability includes two components: the ability to turn in a small radius circle (turning radius) and the ability to turn at high rate (agility). Fish use different patterns, or gaits, of locomotion to swim at different speeds. Their primary gaits are routine swimming powered by the median and paired fins, cruising and sprinting with the body and tail fins, and fast start accelerations using the body and tail fins. Maneuverability differs between gaits, and experiments will be performed to measure maneuverability in each gait using mazes, circular raceways, and fast start trials. Maneuverability will be measured using frame-by-frame analysis of movie or video recordings. Three fish species varying in body shape and fin location will be studied. Measurements of maneuverability during feeding around obstacles and movement through mazes will determine whether how shape affects motor performance (maneuverability) and energy gain during median and paired fin swimming. During sprints, fish are expected to reduce speed to turn. This contrasts with current theory for fish, which may be based on sub-maximum performance levels. Analysis of fast-start maneuvers will test a unified model in which overall performance depends on speed, the timing of a turn and its radius. These variables determine the general pattern of the behavior, the specifics of linear acceleration and deceleration patterns and the final escape trajectory. The research will provide detailed measurements of maneuverability in various activities and a unified approach to intra- and inter-specific variation in swimming behavior. Because maneuverability may constrain habitat selection, the research should contribute to solving problems like the rehabilitation of aquatic habitat. Understanding the factors that limit speed and maneuverability will facilitate construction design that minimizes fish losses due to entrainment in industrial practices.