Repeated vertical movements of mature anguillid eels in a lake
Repeated vertical movements of mature anguillid eels in a lake
复制标题
成熟鳗鱼在湖中反复垂直运动
DOI：
10.1071/mf15217
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Miyazaki N
中科院分区：
文献类型：
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作者：
Watanabe YY;Arai T;Limbong D;Mberato Y;Miyazaki N
繁殖洄游是鳗鲡生活史上的一个重要阶段。然而，迁移鳗鱼的精细尺度行为仍然未知，主要是由于难以将高分辨率记录设备连接到这些小型硬骨鱼并从中恢复。我们用一个带有定时释放系统的小型加速器对成熟的安圭拉和A. marmorata在湖波索，印度尼西亚，在前迁移期间。鳗鱼在水柱（最大深度77米）中重复上下运动，在较浅的俯仰角下下降较慢，不太活跃，然后在较陡的俯仰角下上升较快，更活跃。不对称的潜水模式表明鳗鱼的负浮力，这是由身体密度的测量证实。反复潜水不太可能代表觅食或体温调节，因为成熟的鳗鱼被认为是快速的，水温随深度变化不大。我们认为，反复潜水是鳗鱼的内部动机，连续游泳，准备海洋迁移的结果，并可能是精力更有效率，如果他们保持在一定的深度游泳。由于垂直运动和非中性浮力的影响，自然界中鳗鱼的游泳能量学可能比以前认为的更复杂。
Reproductive migration is a critical phase in the life history of anguillid eels. Nevertheless, fine-scale behaviours of migrating eels remain unknown, primarily due to the difficulty in attaching high-resolution recording devices to, and recovering them from, these small-sized teleosts. We attached a small accelerometer with time-scheduled release system to mature Anguilla celebesensis and A. marmorata in Lake Poso, Indonesia, during the pre-migration period. The eels repeated up-and-down movements in the water column (maximum depth, 77m), with slower, less active descents at shallower pitch angles, followed by faster, more active ascents at steeper pitch angles. The asymmetric diving pattern indicates negative buoyancy of the eels, which was confirmed by the measurements of body densities. The repeated diving is unlikely to represent foraging or thermoregulation because mature eels are thought to fast and water temperature changed little with depth. We suggest that the repeated diving is a result of the eels’ internal motivation for continuous swimming in preparation for oceanic migration, and is possibly energetically more efficient than if they keep swimming at a certain depth. The swimming energetics of eels in nature might be more complicated than previously thought because of the effect of vertical movements and non-neutral buoyancy.