School of Natural Sciences, Macquarie University, NSW, Australia.
PeerJ. 2024 Sep 25;12:e18152. doi: 10.7717/peerj.18152. eCollection 2024.
Many animals possess high-contrast body patterns. When moving, these patterns may create confusing or conflicting visual cues that affect a predator's ability to visually target or capture them, a phenomenon called motion dazzle. The dazzle patterns may generate different forms of optical illusion that can mislead observers about the shape, speed, trajectory and range of the animal. Moreover, it is possible that the disruptive visual effects of the high contrast body patterns can be enhanced when moving against a high contrast background. In this study, we used the humbug damselfish ( to model the apparent motion cues of its high contrast body stripes against high contrast background gratings of different widths and orientations, from the perspective of a predator. We found with higher frequency gratings, when the background is indiscriminable to a viewer, that the humbugs may rely on the confusing motion cues created by internal stripes. With lower frequency gratings, where the background is likely perceivable by a viewer, the humbugs can rely more on confusing motion cues induced by disruption of edges from both the background and body patterning. We also assessed whether humbugs altered their behaviour in response to different backgrounds. Humbugs remained closer and moved less overall in response to backgrounds with a spatial structure similar to their own striped body pattern, possibly to stay camouflaged against the background and thus avoid revealing themselves to potential predators. At backgrounds with higher frequency gratings, humbugs moved more which may represent a greater reliance on the internal contrast of the fish's striped body pattern to generate motion dazzle. It is possible that the humbug stripes provide multiple protective strategies depending on the context and that the fish may alter their behaviour depending on the background to maximise their protection.
许多动物具有高对比度的身体图案。当它们移动时，这些图案可能会产生令人困惑或冲突的视觉提示，影响捕食者对它们的视觉定位或捕捉能力，这种现象称为运动炫晕。炫晕图案可能会产生不同形式的光学错觉，从而使观察者对动物的形状、速度、轨迹和范围产生误解。此外，当动物在高对比度背景下移动时，高对比度身体图案的干扰视觉效果可能会增强。在这项研究中，我们使用了拟态雀鲷（）来模拟其高对比度身体条纹相对于不同宽度和方向的高对比度背景光栅的运动错觉，从捕食者的角度来看。我们发现，对于更高频率的光栅，当背景对观察者不可分辨时，拟态雀鲷可能依赖于内部条纹产生的令人困惑的运动错觉。对于更低频率的光栅，背景很可能被观察者感知，拟态雀鲷可以更多地依赖于背景和身体图案边缘干扰所产生的令人困惑的运动错觉。我们还评估了拟态雀鲷是否会根据不同的背景改变它们的行为。拟态雀鲷在与自身条纹身体图案具有相似空间结构的背景下，整体上会更靠近并移动得更少，可能是为了保持与背景的伪装，从而避免向潜在的捕食者暴露自己。在具有更高频率光栅的背景下，拟态雀鲷移动得更多，这可能代表它们更多地依赖于鱼的条纹身体图案的内部对比度来产生运动炫晕。拟态雀鲷条纹可能提供多种保护策略，具体取决于环境，并且鱼可能会根据背景改变行为，以最大限度地保护自己。
