Data from: Resemblance to the enemy's eyes underlies the intimidating effect of eyespots

Eyespots of some prey are known to deter predators, but the reason for this response has not yet been established, and thus the taxonomically widespread occurrence of this color pattern has remained an evolutionary conundrum. Two alternative hypotheses propose that (1) the eyelike appearance of the pattern falsely indicates the presence of the predator's own enemy or that (2) predators are hardwired to be cautious towards conspicuous prey. Previous research has mainly pertained to eyespots in butterflies. Here we tested the hypothesis that eyespots resemble eyes by utilizing the lateral position of eyes in fishes. This allowed us to produce eyelike displays that did not have the round appearance of eyespots. Our study indicates that eye mimicry is an important factor evoking hesitation in predators. Moreover, we present direct evidence that this is because predators associate eyelike displays with the threat posed by their own enemies.已知部分猎物的眼斑（eyespots）可对捕食者产生威慑作用，但该防御效应背后的具体机制尚未阐明，因此这种在分类学上广泛分布的体色模式始终是一个演化谜题。目前存在两种互斥假说：其一，该类眼状图案的类眼外观会虚假地暗示捕食者自身天敌的存在；其二，捕食者天生会对具有醒目特征的猎物保持警惕。既往相关研究主要聚焦于蝴蝶的眼斑。本研究借助鱼类眼部的侧位分布特征，对"眼斑可模拟眼部"这一假说进行了验证，由此构建出不具备典型眼斑圆形外观的类眼展示图案。研究结果表明，眼部拟态是促使捕食者产生迟疑行为的重要因素。此外，本研究还提供了直接证据，证明该效应的产生是由于捕食者会将类眼展示与自身天敌带来的威胁建立关联。