TOKYO (AP) – Scientists have discovered the ultimate case of regeneration: some beheaded sea snails can find completely new hearts and bodies.
This “wonder of nature,” reported Monday in a biology journal, could help scientists better understand and address human tissue regeneration.
Biology researcher Sayaka Mitoh said she likes to study Japanese sea snails because they are small, cute and weird. They can even photosynthesize briefly as a plant that extracts food from the sun.
One day, in the laboratory, he saw something bizarre: a sea slug decapitated and his head continued to move and live. Then a few more did the same, according to a study in Current Biology.
So the doctoral student and professor of aquatic ecology at the Women’s University of Nara, Yoichi Yusa, tried it themselves, cutting off the heads of 16 sea snails. Six of the creatures began to regenerate, three succeeding and surviving. One of the three even lost and regained his body twice. Two different species of Japanese snails did this regeneration trick.
Other creatures can throw body parts when needed, such as when some lizards leave their tails to escape a predator, in a biological phenomenon called autotomy.
“We believe this is the most extreme case of autotomy,” Yusa said. “Some animals can automate their legs or appendages or tails, but no other animal sheds its entire body.”
Scientists believed that such a relatively large animal – one species of sea snail can grow up to 6 inches long – could not survive without a heart pumping blood and nutrients to the brain, said the Canadian marine biologist Susan Anthony, who was not part of the study.
But the same thing that makes this species spectacular is probably what helps her pull off the trick, Anthony and Yusa said.
When these sea snails eat a certain type of algae, they can photosynthesize their food from sunlight and oxygen, just like a plant, for about 10 days, Yusa said. What probably happens after beheading is that the head acts like a plant, he said. It turns a shade of green and gets its energy from oxygen and sunlight. Becoming small helps, he said.
These species probably developed farming as a way to fight parasites, Mitoh and Yusa said.
It is possible that humans can learn something useful from sea creatures, several scientists said. What is particularly interesting is that these sea snails are more complex than flatworms or other species known to regenerate, said Nicholas Curtis, a biology professor at Ave Maria University who was not part of the study.
“Of course, it’s a wonder of nature, but understanding the molecular mechanisms involved could help us understand how our cells and tissues can be used to repair damage,” Curtis said in an email.
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