Data from: Field swimming behavior in largemouth bass deviates from predictions based on economy and propulsive efficiency

Locomotion is energetically expensive. This may create selection pressures that favor economical locomotor strategies, such as adoption of low cost speeds and efficient propulsive movements. For swimming fish the energy expended to travel a unit distance, or cost of transport (COT), has a U-shaped relationship to speed. The relationship between propulsive kinematics and speed summarized by the Strouhal number (St = fA/U, where f is tail beat frequency, A is tail tip amplitude in m and U is swimming speed in m s<SUP>-1</SUP>) allows for maximal propulsive efficiency where 0.2<St<0.4. Largemouth bass adopted field speeds that were generally below the range predicted to minimize their COT. This may reflect speed modulation to meet competing functional demands such as enabling effective prey detection and capture. St exceeded the optimal range for the lowest observed swimming speeds. Mechanical and physiological constraints may prevent adoption of efficient St during low-speed swimming.

运动的能量消耗代价高昂。这可能会形成选择压力，青睐更具经济性的运动策略，例如采用低能耗运动速度与高效的推进运动模式。对于游泳鱼类而言，单位距离运动的能量消耗，即运动成本（cost of transport, COT），与运动速度呈U型相关关系。推进运动学与运动速度之间的关联可通过斯特劳哈尔数（Strouhal number, St = fA/U，其中f为尾拍频率、A为尾尖摆幅（单位：m）、U为游泳速度（单位：m·s⁻¹））表征，当0.2<St<0.4时可实现最优推进效率。大口黑鲈（Largemouth bass）的野外运动速度通常低于理论上可使其运动成本最小化的速度区间。这可能反映了其通过速度调控以应对多重竞争性功能需求，例如实现高效的猎物探测与捕获行为。在观测到的最低游泳速度下，斯特劳哈尔数超出了最优区间。机械与生理层面的约束因素，可能使得其在低速游泳时无法采用高效的斯特劳哈尔数区间。