Behavioural thermoregulation of chum salmon during homing migration in coastal waters.
Behavioural thermoregulation of chum salmon during homing migration in coastal waters.
复制标题
沿海水域归巢迁徙过程中鲑鱼的行为温度调节。
DOI：
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发表时间：
2000
影响因子：
2.8
通讯作者：
Y. Naito
中科院分区：
文献类型：
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作者：
H. Tanaka;Y. Takagi;Y. Naito
建议归巢太平洋鲑鱼在沿海水域迁徙时，利用浅水中的方向线索。由于鲑鱼是典型的冷水鱼，它们可能不得不在收集方向信息的同时应对温暖的表面水。从10月初到12月，我们使用微型数据记录器研究了31条自由放养鲑鱼Oncorhynchus keta的行为体温调节。10月初，地表水温度约为20摄氏度，12月降至约12摄氏度。水温的季节变化显著地改变了鲑鱼的行为，从深潜水转向浅水游泳。10月份，鲑鱼经常下潜到超过100米的深度。随着海面和底层水温差的增加，深潜的持续时间有延长的趋势。结果表明，鲑鱼寻求最凉爽的避暑场所，它们可以通过垂直运动来利用。热避难所可能是鲑鱼将新陈代谢能量成本降至最低的一种方式；然而，鲑鱼一再回到地表水柱。我们发现，鲑鱼的表面游动与凉爽的覆盖水的存在呈正相关，因为覆盖的水可能包含河流水。这表明，当鲑鱼受到高度集中的定向线索时，往往容易发生风险。12月份的鲑鱼大部分时间都在浅水中度过。这些发现表明，鲑鱼根据海洋的水文结构调整了它们的行为策略，以便在获取方向线索和行为体温调节之间取得平衡。
Homing Pacific salmon are suggested to utilise directional cues in shallow water while migrating in coastal waters. Since salmonids are typical cold-water fish, they may have to cope with warm surface water while gathering directional information. We studied behavioural thermoregulation of 31 free-ranging chum salmon Oncorhynchus keta using micro data loggers off the Sanriku coast from early October to December. The surface water temperature was approximately 20 degrees C in early October and decreased to approximately 12 degrees C in December. The seasonal change of water temperature transformed the behaviour of salmon markedly from deep diving to shallow swimming. In October, salmon frequently dived to depths exceeding 100 m. Duration of deep dives tended to be prolonged as the thermal difference between sea surface and bottom water increased. The results indicated that salmon sought the coolest thermal refuge that they could exploit by vertical movement. Thermal refuge could be a way for salmon to minimise metabolic energy cost; however, salmon repeatedly returned to the surface water column. We found a positive correlation between surface swimming of salmon and the presence of cool covering water, which could contain river waters. This suggests that salmon tend to be risk-prone when subjected to a high concentration of directional cues. Salmon in December spent most of their time in shallow water. These findings suggest that salmon adjusted their behavioural strategy with the hydrographic structure of the sea in order to achieve a balance between acquiring directional cues and behavioural thermoregulation.