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

金枪鱼、鳕鱼、马林鱼、旗鱼以及像大头鲨和大白鲨这样的鲨鱼都有一个共同的属性，那就是它们有能力并且需要持续快速地游泳。这种游泳要求迫使这些物种消耗相当大的新陈代谢能量，正因为如此，它们经常被描述为“高性能”鱼类。这项研究调查了高性能鳃的功能形态，它必须能够提供足够的氧气来为鱼的运动提供动力，并承受持续的水通过它们所施加的结构严苛。这项研究项目的重点是确定鳃发生了什么变化，既增加了摄氧量，又提供了承受与快速、持续游泳相关的高压通风水流所需的僵硬。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之间的合作提供了研究鳃微结构和流体力学所需的专业知识。光学和扫描电子显微镜将被用来建立计算流体动力学模型的鳃水流动。这些模型将与水在不同物种的鳃中流动的体外研究进行比较，体内的鳃研究将在一个大型水洞中对Mako鲨鱼进行。这些不同鱼群的鳃提供了一个令人信服的模型来检验呼吸功能进化趋同的广度和细节。这项研究将使不同的学生接触到有目的的、基于假设的研究，并将提供关于许多比较生理学家认为最复杂的动物器官：鳃的额外知识。这项研究的结果将在圣地亚哥的桦树水族馆通过以数学和科学为主题的K-12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.