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Temperature control of Atlantic salmon (Salmo salar) smolt migration was tested using a novel technique allowing nearly continuous monitoring of behavior with complete control over environmental conditions. Parr and presmolts were implanted with passive integrated transponder tags, placed in simulated streams, and monitored for upstream and downstream movements. Beginning 18 April, temperature was increased 1 °C every third day (advanced), fourth day (ambient), and tenth day (delayed). Smolt downstream movements were initially low, peaked in mid-May, and subsequently declined under all conditions. Parr downstream movements were significantly lower than those of smolts in all treatments (0.8 ± 0.5 movement·day ^–1 versus 26.5 ± 4.5 movements·day ^–1 , mean ± SE) and showed no increase. At delayed temperatures, smolts sustained downstream movements through July; those under ambient and advanced conditions ceased activity by mid-June. Initiation and termination of downstream movements occurred at significantly different temperatures but at the same number of degree-days in all treatments. Physiological changes associated with smolting (gill Na ⁺ ,K ⁺ -ATPase activity and plasma thyroxine) were coincident with behavioral changes. This is the first evidence of a behavioral component to the smolt window. We found that temperature experience over time is more relevant to initiation and termination of downstream movement than a temperature threshold.

利用一种新的技术, 可以在完全控制环境条件的情况下, 对大西洋鲑鱼 (Salar salar安大略鳟) 迁移行为的温度控制进行了连续监测。将幼鲑和二龄前鲑鱼植入无源集成转发器标签，放置在模拟流中，并监测上游和下游的运动。从4月18 日开始，温度没第三天（提前组），第四天（常规组）和第十天（延迟组）升高1℃。二龄鲑鱼在下游的运动起初很低，五月中旬达到最高，随后在所有条件下均下降。在所有试验中，幼鲑在下游的运动均显著低于二龄鲑鱼（分别为0.8± 0.5 movement·day ^–1 和 26.5 ± 4.5 movements·day ^–1，平均值 ± SE）并且显示没有增加。在延迟组的温度下, 鲑鱼的下游运动在7月份持续了整个月；在常规组和提前组的条件下，鲑鱼的下游运动在六月中旬停止。鲑鱼下游运动的启动和终止发生在显著不同的温度下，但在所有实验中的度-天的数量是相同的。幼鲑相关的生理变化（钠钾泵活性和血浆甲状腺）与行为变化是一致的。这是对幼鲑窗口期行为组成的第一个证据。我们发现, 随着时间的推移, 温度体验与下游运动的启动和终止比温度阈值更相关。我们发现, 经历温度的时间积累（积温）与下游运动的启动和终止比温度阈值相关性更强。

参考文献： Evidence for cumulative temperature as an initiating and terminating factor in downstream migratory behavior of Atlantic salmon (Salmo salar) smolts