Researchers in Japan have discovered that two types of sea snail can decapitate themselves and grow new bodies. The results were published this week in the journal Current Biology.
“These snails have a small groove that separates their head from their foot, and it’s like a weak spot in the body,” says Patrick Krug, a marine biologist at Cal State LA. “And it seems like they can literally pull their heads off of their own bodies by contracting their muscles. And the head just crawls away and throws the body away. ”
Why do the snails do this? Parasitic infections.
“There are… crustaceans, like small shrimp, that burrow into the snail’s body and infect it permanently. And there really is no way for the snails to get rid of them other than to throw away the body. So the hypothesis of these researchers is that this is an adaptation to get rid of a parasitized body and start over. ”
And it takes these snails one to three weeks to grow their bodies back, says Krug.
Other organisms that can do something similar, like starfish, which can regrow an entire body from an arm, and flatworms, which can regrow a head or half of their body. Krug says, however, that these animals have very simple bodies, with a diffuse network of nerves, no brain, and no entire organ system.
In contrast, these snails have a heart, kidneys, digestive system, and reproductive organs. “It’s pretty amazing that a head by itself can grow the whole body with all these organ systems.”
He continues, “So it’s exciting to think about what this could mean for regenerative medicine and for applications in biotechnology. Because I just don’t think people thought that an animal of this complexity was capable of anything like that at all. So it opens the door to what we can possibly develop. “