Disentangling the functional roles of morphology and motion in the swimming of fish.
Disentangling the functional roles of morphology and motion in the swimming of fish.
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DOI：
10.1093/icb/icq057
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发表时间：
2010-12
影响因子：
2.6
通讯作者：
E. Tytell;I. Borazjani;F. Sotiropoulos;T. Baker;E. Anderson;G. Lauder
中科院分区：
文献类型：
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作者：
E. Tytell;I. Borazjani;F. Sotiropoulos;T. Baker;E. Anderson;G. Lauder
在鱼类中，身体的形状和游泳模式通常是相关的。身体细长的鱼类，如鳗鱼、七鳃鳗和许多鲨鱼，倾向于以鳗鱼状的方式游泳，在这种模式下，身体的大部分以高幅度波动。相比之下，尾巴宽大，尾部狭窄的鱼倾向于以脉管状的方式游泳，尾巴以高幅度波动。这类鱼也倾向于有不同的尾流结构。弧形游泳者通常在每个尾拍产生两个交错的漩涡和强大的下游喷流，而鳗形游泳者产生更复杂的尾流，每个尾拍至少包含两对漩涡，下游水流相对较少。这些差异是不同的游泳模式还是不同的体型造成的，还是两者兼而有之？解开功能角色需要一个多管齐下的方法，使用活鱼的实验以及计算模拟和物理模型。我们介绍了游动的鳗鱼(鳗形)、蓝鳍太阳鱼(心型)和彩虹鲑鱼(心型)的实验结果，这些结果显示了尾流和游泳性能的差异。用计算机模拟了具有真实感的体型和两种游动模式：正常鱼形和七鳃鳗，然后是鱼形和七鳃鳗。模拟尾迹(单涡排与双涡排)的总体结构强烈依赖于Strouhal数，而体型影响涡排的复杂性，游动方式的影响最小。即使尾流的微小差异也会影响表现：实验和计算结果都表明，鳗形游泳者在较低的游泳速度下更有效率，而心血管状游泳者在高速度下更有效率。在高雷诺数下，七鳃鳗形状的游泳者产生的尾流比鲱鱼形状的游泳者更复杂，与实验结果相似。最后，我们给出了一个简单的扑翼物理模型的结果，使用不同弯曲刚度的鳍。当以相同的方式驱动时，不同刚度的鳍以不同的运动学以不同的速度推进自己。未来的实验和计算工作将需要考虑鳗形和脉管状游泳模式产生的潜在机制，因为通常情况下，鳗状游泳者往往没有心血管游泳者那么僵硬。
In fishes the shape of the body and the swimming mode generally are correlated. Slender-bodied fishes such as eels, lampreys, and many sharks tend to swim in the anguilliform mode, in which much of the body undulates at high amplitude. Fishes with broad tails and a narrow caudal peduncle, in contrast, tend to swim in the carangiform mode, in which the tail undulates at high amplitude. Such fishes also tend to have different wake structures. Carangiform swimmers generally produce two staggered vortices per tail beat and a strong downstream jet, while anguilliform swimmers produce a more complex wake, containing at least two pairs of vortices per tail beat and relatively little downstream flow. Are these differences a result of the different swimming modes or of the different body shapes, or both? Disentangling the functional roles requires a multipronged approach, using experiments on live fishes as well as computational simulations and physical models. We present experimental results from swimming eels (anguilliform), bluegill sunfish (carangiform), and rainbow trout (subcarangiform) that demonstrate differences in the wakes and in swimming performance. The swimming of mackerel and lamprey was also simulated computationally with realistic body shapes and both swimming modes: the normal carangiform mackerel and anguilliform lamprey, then an anguilliform mackerel and carangiform lamprey. The gross structure of simulated wakes (single versus double vortex row) depended strongly on Strouhal number, while body shape influenced the complexity of the vortex row, and the swimming mode had the weakest effect. Performance was affected even by small differences in the wakes: both experimental and computational results indicate that anguilliform swimmers are more efficient at lower swimming speeds, while carangiform swimmers are more efficient at high speed. At high Reynolds number, the lamprey-shaped swimmer produced a more complex wake than the mackerel-shaped swimmer, similar to the experimental results. Finally, we show results from a simple physical model of a flapping fin, using fins of different flexural stiffness. When actuated in the same way, fins of different stiffnesses propel themselves at different speeds with different kinematics. Future experimental and computational work will need to consider the mechanisms underlying production of the anguilliform and carangiform swimming modes, because anguilliform swimmers tend to be less stiff, in general, than are carangiform swimmers.