Stealth and deception: Adaptive motion camouflage in hunting broadclub cuttlefish.

Maintaining camouflage while moving is a challenge faced by many predators. Some exploit background motion to hide while hunting, and others may use coloration and behavior to generate motion noise that impairs detection or recognition. Here, we uncover a unique form of motion camouflage, showing that broadclub cuttlefish pass dark stripes downward across their head and arms to disguise their hunting maneuvers. This "passing-stripe" display reduces the probability of response to predatory expanding stimuli by prey crabs in a lab-based experiment, is modulated according to approach speed during a hunt, and generates a motion pattern that is different from that of looming predators. This form of motion camouflage likely functions by overwhelming the threatening motion of the approaching predator with nonthreatening downward motion generated by the rhythmic stripes.