Claireaux Guy, Handelsman Corey, Standen Emily, Nelson Jay A
Station Mediterraneenne de l'Environnement Littoral, 1 Quai de la Daurade, Sete 34200, France.
Physiol Biochem Zool. 2007 Mar-Apr;80(2):186-96. doi: 10.1086/511143. Epub 2007 Jan 10.
Studies of locomotor performance have contributed to the elucidation of how suborganismal traits ultimately relate to fitness. In terrestrial populations, exploring the physiological and environmental contributions to whole-animal performance measures has improved our understanding of phenotypic selection. Conversely, very little is known about the links between phenotypic selection and swimming abilities in fish. Most research on swimming performance in fish has focused on morphological, physiological, and biochemical traits contributing to performance or has used swimming performance as a measure of environmental suitability. Few studies have explored how swimming performance is integrated with life-history traits or contributes to Darwinian fitness. In addition, while there are many studies on how the environment influences the swimming performance of fish, few have been done at the individual level. The objective of this study was to broaden our understanding of the relevance of fish swimming performance studies by testing the hypothesis that swimming performance (endurance and sprint) is ontogenetically and temporally stable across fluctuating environmental conditions. We found that individual sprint performances recorded at 12 degrees C were significantly repeatable after a 4-wk acclimation to 22 degrees C, although relative sprint performance of fish that survived 6 mo of natural conditions in a mesocosm was not significantly repeatable. Endurance swimming performance, as measured by critical swimming speed (U(crit)) before and after the 6-mo exposure to simulated natural conditions, was significantly repeatable within survivors. Relative sprint and critical swimming performances were not significantly related to each other. We concluded that within a time frame of up to 6 mo, the swimming performances of individual bass are ontogenetically nearly stable (sprint) to stable (endurance) despite large fluctuations in environmental conditions. Moreover, because they rely on different physiological performance traits, critical swimming and sprinting follow different patterns of change. This observation suggests the absence of a trade-off between these two swimming modes and introduces the possibly of independent selection trajectories.
运动表现的研究有助于阐明亚机体特征最终如何与适应性相关联。在陆生种群中，探索对全动物表现指标的生理和环境贡献，增进了我们对表型选择的理解。相反，关于鱼类表型选择与游泳能力之间的联系，我们所知甚少。大多数关于鱼类游泳表现的研究都集中在有助于表现的形态、生理和生化特征上，或者将游泳表现用作环境适宜性的衡量标准。很少有研究探讨游泳表现如何与生活史特征相结合或对达尔文适应性有何贡献。此外，虽然有许多关于环境如何影响鱼类游泳表现的研究，但很少是在个体层面进行的。本研究的目的是通过检验以下假设来拓宽我们对鱼类游泳表现研究相关性的理解：游泳表现（耐力和冲刺）在波动的环境条件下在个体发育和时间上是稳定的。我们发现，在适应4周22摄氏度后，12摄氏度下记录的个体冲刺表现具有显著的重复性，尽管在中宇宙中经历6个月自然条件存活下来的鱼类的相对冲刺表现没有显著的重复性。在6个月模拟自然条件暴露前后，通过临界游泳速度（U(crit)）测量的耐力游泳表现，在存活者中具有显著的重复性。相对冲刺表现和临界游泳表现之间没有显著相关性。我们得出结论，在长达6个月的时间范围内，尽管环境条件波动很大，但个体鲈鱼的游泳表现在个体发育上几乎是稳定的（冲刺）到稳定的（耐力）。此外，由于它们依赖于不同的生理表现特征，临界游泳和冲刺遵循不同的变化模式。这一观察结果表明这两种游泳模式之间不存在权衡，并引入了独立选择轨迹的可能性。
