Evaluation of seasonal and daily changes of plasma thyroxine and cortisol levels in wild masu salmon Oncorhynchus masou, sampled by a Japanese fishing method
Evaluation of seasonal and daily changes of plasma thyroxine and cortisol levels in wild masu salmon Oncorhynchus masou, sampled by a Japanese fishing method
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通过日本捕捞方法采样的野生马苏鲑鱼 Oncorhynchus masou 血浆甲状腺素和皮质醇水平的季节性和每日变化评估
DOI：
10.1111/jfb.12510
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发表时间：
2014
影响因子：
2
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Munakata A.;Miura G.;and.Matsuda;H.
开发了一种新的鱼类取样方法，使用日本诱饵钓竿（8-9米碳棒和尼龙线，带有一个小细钢丝单钩），这被认为是捕捉野生鲑鱼幼鱼低取样压力。使用这种方法，在日本本州岛北方沿海河流（气仙河; 44 km）的邻近地点，检查了野生幼鱼、马苏鲑8月和9月捕获的0+和1+龄幼仔血浆T4和皮质醇水平较低。3月，一些一岁（1岁以上）的鱼，这是判断为前小鲑鱼，和小鲑鱼主要出现在中下游，而幼鱼（0岁以上和1岁以上幼鱼）继续出现在上游和中游。3月，1岁以上幼鱼和幼鱼的血浆T4水平较高，而1岁以上幼鱼的水平较低。在2008年3月至2010年3月期间，1岁以上幼鱼和幼鱼的血浆T4水平从3月初至3月中旬较高，而1岁以上幼鱼的血浆皮质醇水平在3月初较低，并在3月中旬增加。根据这些数据，血浆皮质醇升高可能发生在血浆T4水平升高之后，从而导致1+年。masouto完成银化并开始向海洋迁移。
A new fish sampling method was developed using a Japanese bait fishing rod (8–9 m carbon rod and a nylon line with a small fine wire single hook), which is considered to catch wild salmonid juveniles with low sampling stress. Using this method, seasonal and daily changes of plasma thyroxine (T4) and cortisol levels were examined in wild parr, pre‐smolts and smolts of masu salmonOncorhynchus masouin contiguous locations in a coastal river (Kesen River; 44 km) in northern Honshu Island, Japan, overlapping the period of smoltification and seaward migration from August to March. Plasma T4and cortisol were low in 0+ and 1+ year parr caught in August and September. In March, some yearling (1+ year) fish, which were judged as pre‐smolts, and smolts appeared mainly in mid and lower reaches, while parr (0+ and 1+ year parr) continued to appear in the upper and mid reaches. In March, 1+ year pre‐smolts and smolts showed high plasma T4levels while the levels of 1+ year parr were low. During March 2008–2010, plasma T4levels of 1+ year pre‐smolts and smolts had high levels from early to mid‐March, whereas plasma cortisol levels of 1+ year smolts were low in early March and increased towards mid‐March. Based on these data, plasma cortisol increases probably occur following the increases of plasma T4levels to lead the 1+ yearO. masouto the completion of smoltification and initiation of seaward migration.