Influence of swimming speed on metabolic rates of juvenile Pacific bluefin tuna and yellowfin tuna
Influence of swimming speed on metabolic rates of juvenile Pacific bluefin tuna and yellowfin tuna
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DOI：
10.1086/510637
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发表时间：
2007-03-01
影响因子：
1.6
通讯作者：
Block, Barbara A.
中科院分区：
文献类型：
--
作者：
Blank, Jason M.;Farwell, Charles J.;Block, Barbara A.
蓝鳍金枪鱼是吸热动物，比热带金枪鱼有更高的温度、心率和心输出量。我们假设蓝鳍金枪鱼心血管输送氧气的能力增加可能与更高的代谢率的进化有关。本研究测量了太平洋蓝鳍金枪鱼 Thunnus orientalis 和黄鳍金枪鱼 Thunnus albacares 幼鱼在 20 摄氏度下在泳道呼吸计中游泳的耗氧量。蓝鳍金枪鱼 (7.1-9.4 kg) 的耗氧量 (Mo-2)。范围从 0.85 体长 (BL) s(-1) 时的 235 +/- 38 mg kg(-1) h(-1) 到 1.80 BL s(-1) 时的 498 +/- 55 mg kg(-1) h(-1)。游泳蓝鳍金枪鱼在0.75至1.0 BL s(-1)速度下的最低代谢率为222 +/- 24 mg O-2 kg(-1) h(-1)。 T. albacares (3.7-7.4 kg) 的 Mo-2 范围为 0.65 BL s(-1) 时的 164 +/- 18 mg kg(-1) h(-1) 至 1.8 BL s(-1) 时的 405 +/- 105 mg kg(-1) h(-1)。在所有测试的游泳速度下，蓝鳍金枪鱼的代谢率都高于黄鳍金枪鱼。在给定的速度下，蓝鳍金枪鱼比黄鳍金枪鱼具有更高的新陈代谢率，并且以更高的尾拍频率和更短的步长游泳。太平洋蓝鳍金枪鱼中记录的较高 Mo-2 与这些鱼的心脏性能提高和心肌细胞兴奋收缩耦合能力增强一致。这些生理特征可能是蓝鳍金枪鱼相对于热带金枪鱼物种的热生态位扩张的基础。
Bluefin tuna are endothermic and have higher temperatures, heart rates, and cardiac outputs than tropical tuna. We hypothesized that the increased cardiovascular capacity to deliver oxygen in bluefin may be associated with the evolution of higher metabolic rates. This study measured the oxygen consumption of juvenile Pacific bluefin Thunnus orientalis and yellowfin tuna Thunnus albacares swimming in a swim- tunnel respirometer at 20 degrees C. Oxygen consumption (Mo-2) of bluefin (7.1-9.4 kg). ranged from 235 +/- 38 mg kg(-1) h(-1) at 0.85 body length (BL) s(-1) to 498 +/- 55 mg kg(-1) h(-1) at 1.80 BL s(-1). Minimal metabolic rates of swimming bluefin were 222 +/- 24 mg O-2 kg(-1) h(-1) at speeds of 0.75 to 1.0 BL s(-1). Mo-2 of T. albacares (3.7-7.4 kg) ranged from 164 +/- 18 mg kg(-1) h(-1) at 0.65 BL s(-1) to 405 +/- 105 mg kg(-1) h(-1) at 1.8 BL s(-1). Bluefin tuna had higher metabolic rates than yellowfin tuna at all swimming speeds tested. At a given speed, bluefin had higher metabolic rates and swam with higher tailbeat frequencies and shorter stride lengths than yellowfin. The higher Mo-2 recorded in Pacific bluefin tuna is consistent with the elevated cardiac performance and enhanced capacity for excitation-contraction coupling in cardiac myocytes of these fish. These physiological traits may underlie thermal-niche expansion of bluefin tuna relative to tropical tuna species.