Light can modify orientation and locomotory behaviors in fish and has been applied to attract or repel migrant fish by inducing positive or negative phototaxis. Here, recently metamorphosed downstream‐migrating Sea Lamprey Petromyzon marinus were exposed to light cues in several orientations and intensities at night under controlled flowing‐water conditions in a laboratory flume. Behaviors and rates of downstream movement were monitored with overhead cameras and nets. When exposed to low‐intensity white light, 16–23% more Sea Lamprey were captured in a net closest to the light cue array compared to a dark control condition, suggesting some degree of positive phototaxis at low light levels (100 lx at a distance of 1 m from the light source). An interaction with the side of the flume (possibly due to varying flow conditions) and light treatment was also observed. At higher light intensities (1,000 lx at 1 m from the source), Sea Lamprey progressed downstream at a lower rate than was observed during dark conditions. After high‐intensity light treatments, fewer Sea Lamprey were observed in the nets at the downstream end of the flume and more Sea Lamprey were observed in the flume or in the release channel compared to dark control trials. Therefore, some photonegative behavior may be expressed at light levels of 1,000 lx or greater, perhaps as an attempt to avoid detection by predators by remaining stationary or seeking shelter. Light may have utility as a cue used for guidance devices to control Sea Lamprey, but further research is needed to define how light intensity and the environment (turbidity, depth, water velocity, and natural habitat features) influence locomotion, changes in swimming depth, and other behavioral responses of downstream‐migrating juvenile Sea Lamprey.

中文翻译：

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可见光的评估作为指导下游移民少年海南鳗的线索

光可以改变鱼的方向和运动行为，并已通过诱导正或负趋光性被用于吸引或排斥迁徙鱼。在这里，最近变质了向下游迁移的南兰伯里在实验室水槽中受控的流水条件下，在夜间将其暴露于不同方向和强度的光线提示下。用高架摄像机和网监控下游运动的行为和速率。当暴露于低强度白光下时，与黑暗对照条件相比，最靠近光线索阵列的网中被捕获的海南鳗的数量要多出16-23％，这表明在低光照水平下（距离100 lx，距离光源1 m）。还观察到了与水槽侧面的相互作用（可能是由于流动条件的变化）和光处理。在较高的光照强度下（距光源1 m处1,000 lx），Sea Lamprey的下游传播速度比黑暗条件下观察到的速度要低。经过高强度光处理后 与黑暗对照试验相比，在水槽下游端的网中观察到的海南Lamp更少，在水槽或释放通道中观察到的海南rey更多。因此，某些光负性行为可能会在1,000 lx或更高的光照水平下表达，这可能是为了避免掠食者通过保持静止或寻找庇护所而察觉。光线可能会用作引导装置来控制南Lamp鳗的线索，但还需要进一步研究来确定光线强度和环境（浊度，深度，水速和自然栖息地特征）如何影响运动，游泳深度的变化，以及下游迁徙的少年南兰伯瑞的其他行为反应。