Scientists discover sea slugs that can self-decapitate and regrow entire body

Gulf Today Report

They say truth is stranger than fiction, and in the animal kingdom that adage couldn’t be truer.

It is a known fact that mankind has barely scratched the surface of the vast ocean bed, where spectacular mysteries still abound.

Time and again creatures we think we understand baffle us with new — and in this case — hair-raising behaviours.

Japanese scientists have discovered a type of sea slug which is capable of cutting off its own head, and not only somehow surviving, but then regenerating a whole new body, including organs.

READ MORE

New study says 90 per cent young women use filter edit their photos before posting

Swiss family buys the most expensive villa in Dubai worth Dhs111 million

In Spain hugs and sea air for Pakistani Covid ICU survivor

While autotomy — the process of casting off a body part — is relatively well-known in the animal kingdom, such as lizards losing their tails to escape predators, this extreme form of self-decapitation is unprecedented.

This occurrence has been found in not just one but two species of sea slugs.

Scientists at Nara Women’s University in Japan, said they were first alerted to the phenomenon when they saw “something unexpected:” a slug they had in their laboratory was slithering around without its body. Or rather, just the head was slithering around, and continuing to feed.

The researchers report that the head, separated from the heart and body, moved on its own immediately after the separation.

Within days, the wound at the back of the head closed. The heads of relatively young slugs started to feed on algae within hours.

They started regeneration of the heart within a week. Within about three weeks, regeneration was complete.

However, despite slugs of various ages apparently giving the self-decapitation technique a go, not all of them survived.

The heads of older individuals didn’t feed and died in about 10 days, the researchers said.

In either case, the headless bodies didn’t regenerate a new head, however, despite being decapitated, many continued to move and/or react to being touched for several days or even months.

Sayaka Mitoh of Nara Women’s University said: “We were surprised to see the head moving just after autotomy.

“We thought that it would die soon without a heart and other important organs, but we were surprised again to find that it regenerated the whole body.”

The scientists said they aren’t sure how the sea slugs are capable of such an extensive regeneration.

But Ms Mitoh suggested there must be “stem-like cells” at the cut end of the neck that are capable of regenerating the body.

They also don’t know exactly why the slugs do this. They said one possibility is that it helps to remove internal parasites that inhibit their reproduction.

Furthermore, they also don’t know what immediate cue prompts the slugs to cast off the rest of the body, and said these are areas for future study.

The research was published in the journal “Current Biology.”