Evolution and Functional Morphology of the Gills of High-Performance Fishes

金枪鱼、鲭鱼、马林鱼、旗鱼，以及像灰鲭鱼和大白鲨这样的鲨鱼都有一个共同的特性，那就是它们有能力和需要持续快速游泳。这种游泳要求迫使这些物种消耗相当大的代谢能量，正因为如此，它们经常被描述为“高性能”鱼类。本研究研究了高性能鳃的功能形态，它必须能够提供足够的氧气来驱动鱼的运动，并且还能承受不断“撞击”水通过它们所施加的结构严性。这个研究项目的重点是确定鳃中发生了什么变化，既增加了氧气的摄取，又提供了承受高压通气水流所需的刚性，这些水流与快速、连续的游泳有关。斯克里普斯海洋研究所的格雷厄姆实验室和加州大学欧文分校的麦克亨利实验室合作，提供了检查鳃微观结构和流体力学所需的专业知识。光学显微镜和扫描电子显微镜将用于构建鳃水流的计算流体动力学模型。这些模型将与不同物种的鳃中水流的体外研究进行比较，并将与在大型水隧道中游泳的灰鲭鲨进行体内鳃研究。这些不同鱼类的鳃为研究呼吸功能进化趋同的广度和细节提供了一个令人信服的模型。这项研究将使各种各样的学生接触到有目的的、基于假设的研究，并将为许多比较生理学家认为是最复杂的动物器官——鳃——提供额外的知识。这项研究的结果将在圣地亚哥的伯奇水族馆通过以主题为基础的K-12数学和科学教育项目向公众展示。

Tunas, mackerels, marlins, swordfish, and sharks like the mako and great white all share a common property, which is their ability and need to swim continuously at fast speeds. This swimming requirement forces these species to expend considerable metabolic energy, and because of this, they are frequently described as "high-performance" fishes. This study investigates the functional morphology of high performance gills, which must be able to supply sufficient oxygen to power fish locomotion and also endure the structural rigor imposed by the continuous "ramming" of water through them. This research project is focused on determining what changes have occurred in the gills to both increase oxygen uptake and provide the rigidity needed to withstand the high-pressure ventilatory water flow associated with fast, continuous swimming. Collaboration between the Graham laboratory at Scripps Institution of Oceanography and the McHenry laboratory at the University of California, Irvine provides the expertise needed to examine both gill microstructure and fluid mechanics. Light and scanning electron microscopy will be used to construct computational fluid dynamic models of gill water flow. These models will be compared to in vitro studies of water flow through the gills of different species and in vivo gill studies will be conducted with mako sharks swimming in a large water tunnel. The gills of these different fish groups offer a compelling model to examine the breadth and detail of evolutionary convergence for respiratory function. The study will bring a diversity of students into contact with purposeful, hypothesis-based research and will provide additional knowledge on what many comparative physiologists regard as the most complex animal organ: the gill. The results of this research will be presented to the public through theme-based K-12 education programs in mathematics and science at the Birch Aquarium in San Diego.