Overview

• Scientists observed four specific arm-wave gestures—'up,' 'side,' 'roll,' and 'crown'—in common and dwarf cuttlefish species.
• Playback experiments demonstrated that cuttlefish reciprocate these gestures, suggesting they function as communication signals.
• The gestures also produce water-borne vibrations, indicating a multimodal communication system involving visual and mechanical signals.
• The exact meanings of the gestures remain unclear, with hypotheses including dominance, courtship, defense, or mood expression.
• The findings, published as a preprint, highlight cuttlefish intelligence and propose machine learning for further decoding their communication.