Functional morphology of undulatory pectoral fin locomotion in the stingray taeniura lymma (Chondrichthyes: dasyatidae)
Functional morphology of undulatory pectoral fin locomotion in the stingray taeniura lymma (Chondrichthyes: dasyatidae)
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发表时间：
1999-12
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通讯作者：
Lisa J. Rosenberger;M. Westneat
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作者：
Lisa J. Rosenberger;M. Westneat
Rajiform运动是一种独特的游泳风格发现在蝙蝠鱼（冰鞋和射线），其中推力是由波动波通过扩大胸鳍。我们研究了鳍运动的运动模式和胸鳍肌肉的运动模式驱动的运动系统在蓝点黄貂鱼Taeniuraeromma。我们在这项研究中的目标是确定波动运动过程中的鳍运动和电机控制的整体模式，以发现这些模式如何随着游泳速度的变化，并将肌肉功能与运动学和胸肌形态相关联。运动学数据记录了5个个体在22 - 55 cm s（-）（1）（0.9-3.0 DL s（-）（1），其中DL是身体圆盘长度）游泳速度范围内的运动学数据。记录了三个个体沿着胸鳍沿着七个位置（四个背侧，三个腹侧）的速度范围（1.2-3.0 DL s（-）（1））的肌电图（EMG）数据。随着游泳速度的增加，鳍拍频率、波速和步长增加，波数和约化频率减少，鳍振幅保持不变。在给定的速度下，个体之间的频率和振幅存在差异。相反的关系被发现，其中高鳍拍频率与低鳍振幅和低鳍拍频率与高鳍振幅相关联。波动运动的运动模式是当波浪沿着鳍从前向后移动时，背侧和腹侧肌肉的交替放电活动。除了在最低速度时，鳍肌在整个鳍的沿着都是活跃的。随着游泳速度和鳍拍频率的增加，后部肌肉的激活时间相对于前部背肌的活动开始时间变得更早。肌肉活动的持续时间在腹侧肌肉中比在背侧肌肉中更长，表明它们在鳍拍周期的动力冲程中起着核心作用。前肌（背肌和腹肌）比后肌在步幅周期中活动的时间相对较长。前部肌肉的前部位置和大的占空因数反映了这些肌肉在初始波产生中的作用。运动学数据与EMG数据的同步记录显示，前背肌和中腹肌主要做正功，而背肌和腹后肌在大多数游泳速度下做负功。
Rajiform locomotion is a unique swimming style found in the batoid fishes (skates and rays) in which thrust is generated by undulatory waves passing down the enlarged pectoral fins. We examined the kinematic patterns of fin motion and the motor patterns of pectoral fin muscles driving the locomotor system in the blue-spot stingray Taeniura lymma. Our goals in this study were to determine overall patterns of fin motion and motor control during undulatory locomotion, to discover how these patterns change with swimming velocity and to correlate muscle function with kinematics and pectoral morphology. Kinematic data were recorded from five individuals over a range of swimming speeds from 22 to 55 cm s(-)(1) (0.9-3.0 DL s(-)(1), where DL is body disc length). Electromyographic (EMG) data were recorded from three individuals over a range of velocities (1.2-3.0 DL s(-)(1)) at seven locations (four dorsal, three ventral) along the pectoral fin. As swimming velocity increases, fin-beat frequency, wavespeed and stride length increase, number of waves and reduced frequency decrease and fin amplitude remains constant. There is variability among individuals in frequency and amplitude at a given speed. An inverse relationship was found in which a high fin-beat frequency is associated with a low fin amplitude and a low fin-beat frequency is associated with a high fin amplitude. The motor pattern of undulatory locomotion is alternate firing activity in the dorsal and ventral muscles as the wave moves along the fin from anterior to posterior. Fin muscles are active along the entire length of the fin except at the lowest speeds. As swimming velocity and fin-beat frequency increase, the time of activation of posterior muscles becomes earlier relative to the onset of activity in the anterior dorsal muscles. The duration of muscle activity is longer in the ventral muscles than in the dorsal muscles, indicating that they play a central role in the power stroke of the fin-beat cycle. The anterior muscles (dorsal and ventral) are active for a relatively longer part of the stride cycle than the posterior muscles. Both the anterior position and the large duty factor of the anterior muscles reflect the role of these muscles in initial wave generation. Synchronous recordings of kinematic data with EMG data reveal that the anterior dorsal and middle ventral muscles do mostly positive work, whereas the dorsal and ventral posterior muscles do negative work at most swimming speeds.