Panetta Deanna, Buresch Kendra, Hanlon Roger T
Marine Biological Laboratory, Woods Hole, MA 02543, USA.
Marine Biological Laboratory, Woods Hole, MA 02543, USA
Biol Lett. 2017 Mar;13(3). doi: 10.1098/rsbl.2017.0070.
Masquerade is a defence tactic in which a prey resembles an inedible or inanimate object thus causing predators to misclassify it. Most masquerade colour patterns are static although some species adopt postures or behaviours to enhance the effect. Dynamic masquerade in which the colour pattern can be changed is rare. Here we report a two-step sensory process that enables an additional novel capability known only in cuttlefish and octopus: morphing three-dimensional physical skin texture that further enhances the optical illusions created by coloured skin patterns. Our experimental design incorporated sequential sensory processes: addition of a three-dimensional rock to the testing arena, which attracted the cuttlefish to settle next to it; then visual processing by the cuttlefish of physical textures on the rock to guide expression of the skin papillae, which can range from fully relaxed (smooth skin) to fully expressed (bumpy skin). When a uniformly white smooth rock was presented, cuttlefish moved to the rock and deployed a uniform body pattern with mostly smooth skin. When a rock with small-scale fragments of contrasting shells was presented, the cuttlefish deployed mottled body patterns with strong papillae expression. These robust and reversible responses indicate a sophisticated visual sensorimotor system for dynamic masquerade.
拟态是一种防御策略，即猎物模仿不可食用或无生命的物体，从而使捕食者对其产生误判。大多数拟态的颜色模式是静态的，不过有些物种会采取姿势或行为来增强这种效果。颜色模式可以改变的动态拟态则很罕见。在此，我们报告了一个两步感官过程，它赋予了一种仅在乌贼和章鱼身上才有的全新能力：改变三维物理皮肤纹理，这进一步增强了由彩色皮肤图案产生的视觉错觉。我们的实验设计包含了连续的感官过程：在测试场地添加一块三维岩石，这吸引乌贼在其旁边停留；然后乌贼对岩石上的物理纹理进行视觉处理，以引导皮肤乳突的表现，皮肤乳突的表现范围可以从完全松弛（皮肤光滑）到充分展现（皮肤凹凸不平）。当呈现一块均匀的白色光滑岩石时，乌贼会移向岩石并呈现出身体均匀的图案，皮肤大多是光滑的。当呈现一块带有对比鲜明的贝壳小碎片的岩石时，乌贼会呈现出斑驳的身体图案，且皮肤乳突表现强烈。这些强大且可逆的反应表明存在一个用于动态拟态的复杂视觉感觉运动系统。
