Determining the source of muscle power for suction feeding in ray-finned fishes

大多数鱼通过将食物吸入嘴里来捕获食物，成功的吸食既快又有力。速度和力量的结合需要来自肌肉的强大力量，但所有这些肌肉力量从哪里来？鱼头肌肉很小，但身体肌肉很大。鱼是否将权力从身体转移到头部，就像棒球投手将权力从腿和核心转移到投掷手臂一样？3D X射线成像的最新发展使直接测量功率成为可能，该项目将使用新技术XROMM(运动形态的X射线重建)来研究不同体型和摄食习性的鱼类。这项研究的意义是为理解30,000种鱼(占所有脊椎动物物种的一半)的身体和头部肌肉的结构和功能提供了一个新的框架，其结果将影响世界各地众多实验室正在进行的关于吸食的生物力学、生态学和进化的研究。该项目将邀请普罗维登斯RI公立学校的孩子参加课外海洋生物科学夏令营，提供机会与传统上在科学界代表性较低的群体的学生一起做有趣的科学项目。该项目将开发一种新技术，VROMM(运动形态视频重建)，具有与XROMM类似的功能，但使用摄像机而不是昂贵的X光机。VROMM将通过使这项技术更广泛地可用来加速研究，并通过技术创新提高美国的经济竞争力。最近对大口鲈鱼的一项研究表明，轴肌为高性能吸食提供了95%以上的动力，但到目前为止，这些结果只来自一种物种。轴肌可能是大多数鱼类吸力的主要来源吗？该项目的目标是测量六种不同体型和与大口黑鱼亲缘关系较远的鱼类的头肌和轴肌的功率能力与吸食所需的功率之间的关系。采用XROMM结合动态腔内铸造法测量口腔瞬时容量变化率，采用压力传感器测量口腔压力。压力乘以体积变化率会得到瞬时吸力。最佳肌肉功率容量(POPT)将根据肌肉质量和鱼肌肉产生的最大功率计算出来，假设在最佳速度下缩短。实际肌肉速度将用XROMM和荧光显微镜测量，并计算速度校正功率容量(PVC)。颅肌和轴肌的PVC将与吸力喂养所需的功率进行比较，以确定颅肌可以贡献的最大功率，从而确定轴肌必须贡献的最小功率。这些结果可能为吸食的研究提供一个新的框架，其中轴向肌肉骨骼系统的解剖学、生物力学和进化应该作为摄食的动力源来研究，或者至少作为游泳和摄食需要之间的折衷来研究。

Most fish capture food by sucking it into their mouths, and successful suction feeding is both fast and forceful. Speed and force combined require high power from muscles, but where does all of that muscle power come from? Fish head muscles are small, but the body muscles are large. Do fish transfer power from their bodies to their heads, similar to the way baseball pitchers transfer power from their legs and core to their throwing arms? Recent developments in 3D X-ray imaging have made it possible to measure power directly, and this project will use the new technology, XROMM (X-ray Reconstruction of Moving Morphology), to study fish with diverse body forms and feeding habits. The significance of this research is a new framework for understanding the structure and function of body and head muscles in 30,000 species of fish (half of all vertebrate species), and the results will impact ongoing research in numerous labs worldwide studying the biomechanics, ecology and evolution of suction feeding. This project will engage children from the Providence RI public schools in an after-school Marine Biology Science Camp, providing an opportunity to do fun science projects with students from groups traditionally underrepresented in the sciences. This project will develop a new technology, VROMM (Video Reconstruction of Moving Morphology), with similar capabilities as XROMM but with video cameras instead of expensive X-ray machines. VROMM will accelerate research by making the technology more widely available and advance US economic competiveness through technological innovation.A recent study of largemouth bass showed that axial muscles provide more than 95% of the power for high-performance suction feeding, but these results so far come from just one species. Might axial muscles be the main source of suction power in most fishes? The goal of this project is to measure the power capacity of cranial and axial musculature relative to the power required for suction feeding in six species of fishes with different body forms and distant phylogenetic relationships to largemouth bass. XROMM combined with the dynamic endocast method will be used to measure instantaneous rate of buccal volume change, and a pressure transducer will be used to measure buccal pressure. Pressure multiplied by the rate of volume change will yield instantaneous suction power. Optimal muscle power capacity (Popt) will be calculated from muscle mass and the maximum power produced by fish muscle, which assumes shortening at the optimal velocity. Actual muscle velocity will be measured with XROMM and fluoromicrometry, and velocity-corrected power capacity (Pvc) calculated. The Pvc for cranial and axial muscles will be compared to the power required for suction feeding to determine the maximum power that cranial muscles can contribute, and therefore the minimum power that axial muscles must be contributing. These results may provide a new framework for studying suction feeding, in which the anatomy, biomechanics, and evolution of the axial musculoskeletal system should be studied as the power source for feeding, or at least as compromises between the needs of swimming and feeding.