High levels of mortality occur in the fingerling production of juvenile Pacific bluefin tuna (PBF, Thunnus orientalis), especially just after transportation from land‐based tanks to sea cages. The survival rate drastically declines within 3 days after transportation. To improve aquaculture efficiency, this problem needs to be resolved. We focused on the body size of juvenile PBF. We conducted two experiments using large‐size (Experiment 1; mean body weight, 11.6 g) and small‐size (Experiment 2; mean body weight, 0.5 g) fish to investigate the appropriate size for transportation. Experiment 1, using large‐size juvenile PBF, showed worse outcomes than the control‐1, including increased mortality induced by collisions due to a prolonged period in a land‐based tank and mortality due to the transportation process. In contrast, Experiment 2, using small‐size juvenile PBF, demonstrated high survival without high rates of mortality, even just after transportation. In addition, there were no differences in growth between the treatments at the end of the experiment. Thus, this study suggests that transportation of smaller PBF juveniles than recommended in past studies could improve aquaculture efficiency because of a higher survival rate and shortened duration of hatchery management.

中文翻译：

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少年太平洋蓝鳍金枪鱼东方金枪鱼（Temminck和Schlegel）运输到海笼的适当尺寸

少年太平洋蓝鳍金枪鱼（PBF，东方金枪鱼）的鱼种生产中发生高死亡率），尤其是从陆上储罐运输到海笼之后。运输后3天内，生存率急剧下降。为了提高水产养殖效率，这个问题需要解决。我们关注青少年PBF的体型。我们使用大型鱼（实验1；平均体重11.6 g）和小型鱼（实验2；平均体重0.5 g）进行了两个实验，以研究适合运输的大小。使用大型少年PBF的实验1显示出比对照-1更差的结果，包括由于陆上坦克的长时间停留而导致的碰撞导致的死亡率增加以及运输过程造成的死亡率增加。相比之下，使用小型少年PBF的实验2甚至在运输后也显示出高存活率而没有高死亡率。另外，实验结束时各处理之间的生长没有差异。因此，这项研究表明，与以往的研究相比，运输较小的PBF幼体可以提高水产养殖效率，因为其成活率更高，孵化场的管理时间较短。