Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
Technical University of Denmark, DTU AQUA, Section for Aquaculture, The North Sea Research Centre, 9850 Hirtshals, Denmark.
J Exp Biol. 2022 May 1;225(9). doi: 10.1242/jeb.243328. Epub 2022 May 9.
Fish perform rapid escape responses to avoid sudden predatory attacks. During escape responses, fish bend their bodies into a C-shape and quickly turn away from the predator and accelerate. The escape trajectory is determined by the initial turn (stage 1) and a contralateral bend (stage 2). Previous studies have used a single threat or model predator as a stimulus. In nature, however, multiple predators may attack from different directions simultaneously or in close succession. It is unknown whether fish are able to change the course of their escape response when startled by multiple stimuli at various time intervals. Pacific staghorn sculpin (Leptocottus armatus) were startled with a left and right visual stimulus in close succession. By varying the timing of the second stimulus, we were able to determine when and how a second stimulus could affect the escape response direction. Four treatments were used: a single visual stimulus (control); or two stimuli coming from opposite sides separated by a 0 ms (simultaneous treatment), 33 ms or 83 ms time interval. The 33 ms and 83 ms time intervals were chosen to occur either side of a predicted 60 ms visual escape latency (i.e. during stage 1). The 0 ms and 33 ms treatments influenced both the escape trajectory and the stage 1 turning angle, compared with a single stimulation, whereas the 83 ms treatment had no effect on the escape trajectory. We conclude that Pacific staghorn sculpin can modulate their escape trajectory only between stimulation and the onset of the response, but the escape trajectory cannot be modulated after the body motion has started.
鱼类会迅速做出逃避反应以避免突然的捕食攻击。在逃避反应中，鱼类会将身体弯曲成 C 形，并迅速转向远离捕食者并加速。逃避轨迹由初始转弯（第 1 阶段）和对侧弯曲（第 2 阶段）决定。以前的研究使用单一威胁或模型捕食者作为刺激。然而，在自然界中，多个捕食者可能会从不同方向同时或连续攻击。目前还不清楚鱼类在受到多个刺激且时间间隔不同时，是否能够改变其逃避反应的方向。太平洋鹿角鱼（Leptocottus armatus）会对连续的左右视觉刺激做出反应。通过改变第二个刺激的时间，可以确定第二个刺激在何时以及如何影响逃避反应的方向。使用了四种处理方法：单一视觉刺激（对照）；或者来自相反两侧的两个刺激，间隔 0 ms（同时处理）、33 ms 或 83 ms。选择 33 ms 和 83 ms 时间间隔是为了使其发生在预测的 60 ms 视觉逃避潜伏期（即第 1 阶段）的任一侧。与单一刺激相比，0 ms 和 33 ms 处理方法会影响逃避轨迹和第 1 阶段的转弯角度，而 83 ms 处理方法对逃避轨迹没有影响。我们得出结论，太平洋鹿角鱼只能在刺激和反应开始之间调节其逃避轨迹，但在身体运动开始后，无法调节逃避轨迹。
