A Hormone Makes Starfish Lose Limb To Survive Predators. Humans Have It Too

The research team at Queen Mary University of London, UK, proposed that when this hormone -- 'ArSK/CCK1' -- is released in response to stress, it triggers a muscle at the base of the starfish's arm to tense, thereby effectively causing it to break off.

Researchers have identified the hormone that triggers a starfish to shed its limbs to survive predators, describing it as being similar to the one controlling appetite in humans.

The research team at Queen Mary University of London, UK, proposed that when this hormone -- 'ArSK/CCK1' -- is released in response to stress, it triggers a muscle at the base of the starfish's arm to tense, thereby effectively causing it to break off. They studied a common European starfish, Asterias rubens.

The authors said the findings, published in the journal Current Biology, revealed a key piece of the puzzle regarding processes which underlie autotomy, or the ability of an animal to detach a body part to escape predatory attacks.