Complexity and simplicity in multispecies octopus-fish groups

Complex communication systems can emerge even among evolutionarily distant species, raising questions about how cues and signals evolve and support coordination. One striking case is the collaborative hunting between octopuses and reef-associated fish, where each partner exploits distinct foraging strengths. Field observations and experiments show that these interactions rely on a mix of passive cues and intentional signals, such as referential gestures. Octopuses adjust their behavior depending on partner species and context, sometimes responding punitively to exploitative fish. Beyond movement, information may also be relayed to other individuals through colour change. This multidimensional dynamic use of signals and cues, based on both movement and potentially color, raises compelling questions about the boundary between passive and active communication, and how much each contributes to group coordination and success. To further probe these mechanisms, we combine field experiments using robotic fish with computational simulations to understand how simple rules and complex cognition jointly shape communication in multispecies hunting groups.