Department of Biomedical Engineering, Ben-Gurion University of the Negev, Be'er Sheva, Israel.
School of Brain Sciences and Cognition, Ben-Gurion University of the Negev, Be'er Sheva, Israel.
Elife. 2024 Jun 3;12:RP92909. doi: 10.7554/eLife.92909.
The archerfish is unique in its ability to hunt by shooting a jet of water from its mouth that hits insects situated above the water's surface. To aim accurately, the fish needs to overcome physical factors including changes in light refraction at the air-water interface. Nevertheless, archerfish can still hit the target with a high success rate under changing conditions. One possible explanation for this extraordinary ability is that it is learned by trial and error through a motor adaptation process. We tested this possibility by characterizing the ability of the archerfish to adapt to perturbations in the environment to make appropriate adjustments to its shots. We introduced a perturbing airflow above the water tank of the archerfish trained to shoot at a target. For each trial shot, we measured the error, i.e., the distance between the center of the target and the center of the water jet produced by the fish. Immediately after the airflow perturbation, there was an increase in shot error. Then, over the course of several trials, the error was reduced and eventually plateaued. After the removal of the perturbation, there was an aftereffect, where the error was in the opposite direction but washed out after several trials. These results indicate that archerfish can adapt to the airflow perturbation. Testing the fish with two opposite airflow directions indicated that adaptation took place within an egocentric frame of reference. These results thus suggest that the archerfish is capable of motor adaptation, as indicated by data showing that the fish produced motor commands that anticipated the perturbation.
射水鱼具有独特的能力，能够从口中射出一股水流来捕食位于水面上方的昆虫。为了准确瞄准，鱼需要克服包括空气-水界面光折射变化在内的物理因素。尽管如此，射水鱼仍然可以在不断变化的条件下以高成功率命中目标。这种非凡能力的一个可能解释是，它通过试错和运动适应过程来学习。我们通过描述射水鱼适应环境变化以对其射击进行适当调整的能力来检验这种可能性。我们在训练射水鱼射击目标的水箱上方引入了扰流空气。对于每次试射，我们测量误差，即目标中心和鱼射出的水流中心之间的距离。扰流空气出现后，立即增加了射击误差。然后，在几轮试验中，误差逐渐减小并最终稳定下来。在消除扰动后，会出现后效，即误差方向相反，但经过几次试验后就会消失。这些结果表明，射水鱼能够适应气流扰动。用两个相反的气流方向测试鱼表明，适应是在以自我为中心的参照系中发生的。因此，这些结果表明射水鱼具有运动适应能力，因为数据表明鱼产生了预期扰动的运动指令。
