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Cuttlefish adjust their shape and color to suit conditions when seeking prey, study shows

A small team of marine biologists at the University of Bristol, in the U.K., working with a colleague from the Regional Research and Innovation Agency of West Papua, Indonesia, has found that wild broadclub cuttlefish adapt their body shape and color in certain ways, depending on circumstances, to hide from unsuspecting prey.

In their study in the journal Ecology, the group spent several months at sea off the coast of New Guinea, filming cuttlefish as they hunted.

West Papua is an Indonesian province on the Bird's Head Peninsula and the Bomberai Peninsula, on the island of New Guinea. Large numbers of cuttlefish live just off its shores. It was to this location that the researchers on this new venture came, hoping to learn more about how cuttlefish use their color-changing ability.

Cuttlefish use their color-changing ability to hide from predators. In this new effort, the research team wanted to know if they also change their colors to help them hide from potential prey. To find out, the team spent several months filming 98 cuttlefish as they hunted for prey, including crabs, shrimp and other crustaceans. The researchers found that the mollusks had four main types of displays they used to camouflage themselves as they approached prey.

They named the first "the leaf," because the cuttlefish would change its coloring to that of a leaf and flatten its body, helping to pull off the deception. The second display they called the "passing stripe"; it involved turning itself dark gray except for a moving black stripe down its back. The added motion, the team found, helped to hide the rest of the body of the cuttlefish as it approached.

They named the third display the "branching coral," in which the cuttlefish raised its arms and splayed them in a way reminiscent of a coral while changing its body color to match. The fourth they called "the pulse"; here, the cuttlefish moved its arms forward and pointed them forward, while dark pulses of color traveled along its body. The researchers were not able to pin down how it helped in catching prey, but found that cuttlefish used it just as often as the other displays.