Sea slugs voluntarily sever their own heads and regrow their bodies

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Sea slug decaptitate themselves

Although sea slugs are uncharismatic – that’s for sure – they have a monumental trick up their sleeve: they are able to voluntarily decapitate themselves and regrow a new body onto their severed head. To put it another way, they remove their body from their head leaving their head unsustained by their heart and body organs but the head lives on.

Sea slug decaptitate themselves

Sea slugs decaptitate themselves. Image: MikeB from images in the public domain.

It is speculated that the head is able to live without the heart and the other organs of the body because they adopt chloroplasts from their algal prey which they incorporate into their bodies and in their head. These chloroplasts are harnessed to provide enough energy from the sun to maintain the head while the body grows back.

Why do they do all this? The scientists are puzzled but they believe that it is a form of detoxification of the body by removing internal parasites which infest the body. If the body is totally removed those parasite are removed to.

The research was carried out from Nara Woman’s University in Japan. They say that two different species of sea slug can do this. It is extremely strange for a creature to shed their body and then regrow it onto their head. It is a form of autotomy which we see in lizards for instance when they shed a part of their tail when attacked.

The scientists initially thought that the reason behind this strange behavior was the same, that they had been attacked, but when they pinched them with tweezers nothing happen so that they come up with a different idea.