When colours speak: context-dependent chromatic expression during predation in Sepia (acanthosepion) pharaonis

Predator-prey encounters constitute high-risk events for both interacting parties. These encounters are accompanied by changes in internal state, notably through increased arousal. Although cephalopods are renowned for their dynamic body patterns, the extent to which these chromatic displays track internal arousal or emotional valence during predation remains largely unresolved. We investigated seven chromatic components expressed by five subadults Sepia (acanthosepion) pharaonis (Ehrenberg, 1831) under controlled variations of prey accessibility, social context, and hunting outcomes to determine whether body-pattern dynamics reflect underlying emotion-like states. Chromatic expression intensified as predation progressed, peaking when prey was held in the arms. This rise was dominated by the Fragmented dark mantle component, which could serve as a potential marker of increased arousal. In contrast, one component - red fins, was selectively upregulated in situations with presumed negative valence, including inaccessible prey or the presence of a conspecific. Papillate skin expression decreased during prey capture, with papillae becoming less prominent at the moment of prey seizure, potentially contributing to improved hydrodynamic efficiency. Together, these findings provide the first evidence that S. pharaonis cuttlefish exhibits context-dependent, dissociable chromatic signatures during prey capture. These differences are consistent with the expression of arousal and valence. Our work offers a quantitative framework for interpreting cephalopod body patterns as indicators of internal states and informs broader theories on the evolution of emotional expression in non-human animals.