PRF: Energetics and Hydrodynamics of Suspension Feeding in Blackfish: Ontogenetic Shift in Feeding Mode

成年悬浮式摄食鱼(如凤尾鱼和鲱鱼)张开嘴游泳，捕获多个猎物。尽管这些鱼具有重要的经济和生态意义，但很少有研究检验关于悬浮饲养的功能形态、能量和水动力学的假说。作为幼年，这些物种是颗粒喂食者，用吸力捕捉个体猎物。从颗粒喂料到悬浮喂料的深刻转变为从机械角度研究悬浮喂料提供了一个理想的机会。呼吸生理学和生物力学技术将被用来检验两个主要假设：第一，幼年黑鱼在张开嘴游泳时，通过口腔和顶腔的水路的水力阻力以及整个身体的水动力阻力显著高于成年黑鱼；其次，在饲养模式之间的转换过程中，饲养的能量成本突然下降。虽然过渡后悬浮喂养的能量成本可能较低，但身体上的限制可能会阻止幼体悬浮喂养。关于在不同饲养模式之间转换所涉及的因素的信息将对浮游生物种群动态、幼鱼和成鱼之间的资源分配以及鱼类悬浮饲养的演变产生影响。加州大学戴维斯分校将担任这一博士后研究奖学金项目的主办机构。这一奖项的有效期为两年。

Adult suspension feeding fishes (e.g., anchovies and mackerels) capture multiple prey by swimming with mouths held open. Despite the economic and ecological importance of these fishes, few studies have tested hypotheses concerning the functional morphology, energetics, and hydrodynamics of suspension feeding. As juveniles, these species are particulate feeders that capture individual prey using suction. The profound shift from particulate feeding to suspension feeding offers an ideal opportunity to investigate suspension feeding from a mechanistic perspective. The techniques of respiratory physiology and biomechanics will be applied to test two main hypotheses: first,that the hydraulic resistance of the water path through the oral and opercular cavities, as well as the hydrodynamic drag of the entire body during swimming with the mouth held open, is significantly higher in juvenile blackfish than in adults; and secondly, that the energetic cost of feeding decreases abruptly over the transition between feeding modes. Although the energetic cost of suspension feeding may be low after the transition, physical constraints may prevent juveniles from suspension feeding. Information on the factors involved in the switch between feeding modes will have implications for plankton population dynamics, resource partitioning between juvenile and adult fishes, and the evolution of suspension feeding in fishes. The University of California at Davis will serve as the host institution for this postdoctoral research fellowship project. The duration of this award is two years.