Geometrical model explains multiple preferred escape trajectories of fish
Geometrical model explains multiple preferred escape trajectories of fish
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几何模型解释了鱼类的多种首选逃逸轨迹
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
P. Domenici
中科院分区：
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作者：
Yuuki Kawabata;Hideyuki Akada;K. Shimatani;Gregory N. Nishihara;Hibiki Kimura;Nishiumi Nozomi;P. Domenici
为了躲避捕食者，许多猎物会进行快速逃跑动作。由此产生的逃逸轨迹(ET)--以逃逸方向相对于捕食者接近路径的角度测量--在避免捕食方面发挥着重要作用。以前的几何模型预测单一的ET；然而，许多动物(鱼类和其他动物类群)显示出高度可变的ET具有多个优先方向。尽管如此高的ET变异性可能会带来不可预测性，阻止捕食者采取反策略，但动物更喜欢特定的多个ETS的原因尚不清楚。在这里，我们构造了一个新的几何模型，其中Tdiff(猎物进入安全区和捕食者到达该入口点之间的时间差)期望最大化。我们通过分析被虚拟捕食者攻击的斑羚的逃逸反应来检验这一预测。在猎物相对于捕食者的每个初始身体方位，我们的模型预测了多模式ET，其中最优ET在Tdiff(Tdiff，1)处，次优ET在Tdiff的第二个局部最大值(Tdiff，2)。我们的实验表明，当Tdiff，1-Tdiff，2可忽略时，猎物使用相似程度的最优或次优ETS，符合不可预测性的思想。实验观测到的ET分布与模型一致，在距捕食者110°~130°和170°~180°处有两个大峰。由于不同的动物类群表现出与这里观察到的相似的多个偏好ETS，这种行为表型可能是融合了最大Tdiff和高度不可预测性的进化的结果。来自许多类群的动物通过使用多个偏好逃逸轨迹来逃避突然逼近的威胁，例如伏击捕食者。然而，为什么使用这些多个首选逃逸轨迹的原因仍不清楚。通过将新构建的模型与经验逃逸反应数据进行拟合，我们证明了看似复杂的多个首选逃逸轨迹可以由一个简单的几何规则产生，该规则最大化了猎物进入安全区和捕食者到达该入口点之间的时间差。我们的结果为了解动物如何从行为和神经感觉角度选择它们的逃逸轨迹开辟了新的研究途径。
To evade predators, many prey perform rapid escape movements. The resulting escape trajectory (ET) – measured as the angle of escape direction relative to the predator’s approach path – plays a major role in avoiding predation. Previous geometrical models predict a single ET; however, many animals (fish and other animal taxa) show highly variable ETs with multiple preferred directions. Although such a high ET variability may confer unpredictability, preventing predators from adopting counter-strategies, the reasons why animals prefer specific multiple ETs remain unclear. Here, we constructed a novel geometrical model in which Tdiff (the time difference between the prey entering the safety zone and the predator reaching that entry point) is expected to be maximized. We tested this prediction by analyzing the escape responses of Pagrus major attacked by a dummy predator. At each initial body orientation of the prey relative to the predator, our model predicts a multimodal ET with an optimal ET at the maximum Tdiff (Tdiff,1) and a suboptimal ET at a second local maximum of Tdiff (Tdiff,2). Our experiments show that when Tdiff, 1–Tdiff, 2 is negligible, the prey uses optimal or suboptimal ETs to a similar extent, in line with the idea of unpredictability. The experimentally observed ET distribution is consistent with the model, showing two large peaks at 110–130° and 170–180° away from the predator. Because various animal taxa show multiple preferred ETs similar to those observed here, this behavioral phenotype may result from convergent evolution that combines maximal Tdiff with a high level of unpredictability.Animals from many taxa escape from suddenly approaching threats, such as ambush predators, by using multiple preferred escape trajectories. However, the reason why these multiple preferred escape trajectories are used is still unknown. By fitting a newly constructed model to the empirical escape response data, we show that the seemingly complex multiple preferred escape trajectories can arise from a simple geometrical rule which maximizes the time difference between when the prey enters the safety zone and when the predator reaches that entry point. Our results open new avenues of investigation for understanding how animals choose their escape trajectories from behavioral and neurosensory perspectives.