Cuttlefish 'mesmerize' their prey with a moving skin pattern, study finds

Maintaining camouflage while moving is a challenge faced by many pursuit predators. In this study published today in Science Advances, the team uncovered a novel form of motion camouflage, whereby the broadclub cuttlefish pass dark stripes downwards across their head and arms to disguise their hunting manoeuvres.

Lead author Dr Matteo Santon from the University of Bristol's School of Biological Sciences said: "Camouflage has predominantly been studied as an adaptation that prey use to hamper their detection or recognition from predators, and almost exclusively focused on still prey as motion tends to disrupt camouflage."

Senior author Dr Martin How explained: "Most cuttlefish rely on stealth to sneak up on prey. Due to their fast colour-changing skin, these remarkable animals have a wider range of options than most when it comes to camouflage while moving."

By taking a prey crab's eye-view, the scientists were able to show that the passing-stripe display is camouflaging the predator while hunting. Their findings suggest that the visual system of the prey may be overwhelmed by the strong motion produced by the stripes, causing them to fail to detect the looming cues of the approaching predator.

Dr Santon added: "To our eyes this dynamic display looks very conspicuous, standing out strongly from the background, but it is exploiting the effect of the strong dynamic motion cues produced by the rhythmic passing stripes to deceive the prey."

And there is more. This species can produce at least three other types of elaborate hunting displays. This is an astonishing variety of adaptations for sneaking up on prey."

He now plans to focus on how the other displays function, and to investigate what makes cuttlefish choose one hunting display over another.

He said: "It was a truly magical experience seeing this species hunting in the wild for the first time. Watching this cuttlefish hunting with the passing-stripe display is like being mesmerised by the tricks of a skilled illusionist."