Data from: Stomatopods detect and assess achromatic cues in contests

Conspicuous, colorful displays are often used by animals to communicate within and between species. Previously, researchers have manipulated specific components of color signals (i.e., hue, total reflectance, and/or chroma) using paints, photographs, videos, or filters. However, these manipulations may not adequately mimic the spectrum of color signals outside the range of human perception. Thus, these methods are inappropriate for organisms with unconventional visual systems, such as stomatopods (mantis shrimp). Here, we describe a novel application of a femtosecond laser to increase total reflectance of the stomatopod meral spot, a distinct area on the raptorial appendage used in territorial contests. Ultrafast lasers provide a programmable way to precisely manipulate patch total reflectance of live stomatopods without causing collateral damage. We tested how experimentally increasing meral spot reflectance impacted receiver behavior during territorial contests. Contests in which receiver stomatopods faced an opponent with a lightened meral spot were shorter and receivers showed increased rates of agonistic behaviors. This result suggests that lighter meral spots indicate lower fighting ability; thus, receivers are more willing to engage in a contest. This research provides the first demonstration that stomatopods can detect and assess achromatic variation in contests. Furthermore, we demonstrate that ultrafast lasers provide a powerful tool to investigate achromatic signaling, particularly for organisms whose size, aquatic habitat, or visual system otherwise prevent realistic alterations to color signals (e.g., butterflies, jumping spiders, or decapod crustaceans). This study advances our knowledge about stomatopod visual communication and offers a valuable tool for future research.动物常通过醒目艳丽的信号展示，完成种内与种间的信息交流。此前，研究者多借助颜料、照片、视频或滤光片等手段，操控色彩信号的特定参数，即色调（hue）、总反射率（total reflectance）及/或彩度（chroma）。然而此类操控手段往往无法精准复刻人类视觉感知范围之外的色彩信号光谱，因此并不适用于具备非典型视觉系统的生物，例如口足类动物（stomatopods，螳螂虾）。 本研究首次将飞秒激光（femtosecond laser）应用于提升口足类动物螯突斑（meral spot）的总反射率：螯突斑是其用于领地争夺的掠肢（raptorial appendage）上的标志性区域。超短脉冲激光可通过程序化方式，精准调控活体口足类动物的螯突斑总反射率，且不会造成附带损伤。 我们通过实验提升螯突斑反射率后，测试了其对领地争夺中接收方行为的影响。当接收方口足类动物面对螯突斑提亮的对手时，领地争夺的持续时长更短，且接收方展现出更高频率的争斗行为（agonistic behaviors）。该结果表明，螯突斑亮度越低，代表其战斗能力越弱，因此接收方更愿意发起争斗。 本研究首次证实，口足类动物可在领地争夺中感知并评估消色差变异（achromatic variation）。此外，本研究证明超短脉冲激光是研究消色差信号传递的有力工具，尤其适用于那些因体型、水生栖息环境或视觉系统限制，无法对色彩信号进行真实模拟改造的生物，例如蝴蝶、跳蛛或十足目甲壳动物（decapod crustaceans）。 本研究加深了我们对口足类动物视觉通信的认知，并为后续研究提供了极具价值的实验工具。