Hoffmann S L, Porter M E
Department of Biological Sciences, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431, USA.
Integr Org Biol. 2019 Jun 22;1(1):obz014. doi: 10.1093/iob/obz014. eCollection 2019.
Maneuvering is a crucial locomotor strategy among aquatic vertebrates, common in routine swimming, feeding, and escape responses. Combinations of whole body and fin movements generate an imbalance of forces resulting in deviation from an initial path. Sharks have elongate bodies that bend substantially and, in combination with pectoral fin rotation, play a role in yaw (horizontal) turning, but previous studies focus primarily on maximal turning performance rather than routine maneuvers. Routine maneuvering is largely understudied in fish swimming, despite observations that moderate maneuvering is much more common than the extreme behaviors commonly described in the literature. In this study, we target routine maneuvering in the bonnethead shark, . We use video reconstruction of moving morphology to describe three-dimensional pectoral fin rotation about three axes to compare to those previously described on yaw turning by the Pacific spiny dogfish. We quantify kinematic variables to understand the impacts of body and fin movements on routine turning performance. We also describe the anatomy of bonnethead pectoral fins and use muscle stimulation to confirm functional hypotheses about their role in actuating the fin. The turning performance metrics we describe for bonnethead sharks are comparable to other routine maneuvers described for the Pacific spiny dogfish and manta rays. These turns were substantially less agile and maneuverable than previously documented for other sharks, which we hypothesize results from the comparison of routine turning to maneuvering under stimulated conditions. We suggest that these results highlight the importance of considering routine maneuvering in future studies. Cinemática del Cuerpo y de las Aletas Pectorales Durante el giro en el eje Vertical en la Cabeza del Tiburón Pala () (Body and Pectoral Fin Kinematics During Routine Yaw Turning in Bonnethead Sharks []).
在水生脊椎动物中，机动是一种至关重要的运动策略，常见于日常游泳、觅食和逃避反应中。全身运动和鳍的运动相结合会产生力的不平衡，从而导致偏离初始路径。鲨鱼具有细长的身体，身体能大幅弯曲，再结合胸鳍的转动，在偏航（水平）转向中发挥作用，但先前的研究主要关注最大转向性能，而非日常机动。尽管观察到适度的机动比文献中通常描述的极端行为更为常见，但鱼类游泳中的日常机动在很大程度上仍未得到充分研究。在本研究中，我们以窄头双髻鲨的日常机动为研究对象。我们使用移动形态的视频重建来描述胸鳍围绕三个轴的三维转动，以便与先前关于太平洋刺鲨偏航转向的描述进行比较。我们量化运动学变量，以了解身体和鳍的运动对日常转向性能的影响。我们还描述了窄头双髻鲨胸鳍的解剖结构，并使用肌肉刺激来证实关于其在驱动鳍方面作用的功能假设。我们为窄头双髻鲨描述的转向性能指标与为太平洋刺鲨和蝠鲼描述的其他日常机动相当。这些转向的敏捷性和机动性明显低于先前记录的其他鲨鱼，我们推测这是将日常转向与受刺激条件下的机动进行比较的结果。我们认为这些结果凸显了在未来研究中考虑日常机动的重要性。窄头双髻鲨日常偏航转向时的身体和胸鳍运动学（）
