Exploding Sea Cucumber Butt Threads Are a New Material

Whoever named the sea cucumber after a vegetable didn't give it enough credit. Yes, sea cucumbers are soft, warty tubes that scoot eyelessly along the seafloor. But they aren't helpless. Some secrete a poison that's deadly to other animals. And some, when threatened, shoot sticky threads out of their anuses to tangle up predators. When researchers collected these bizarre weapons and tested them in the lab, they discovered a material that's unique among sea creatures. The threads that sea cucumbers use to trap their enemies are called Cuvierian tubules. Inside the bodies of certain species, the waiting tubules float like limp noodles. When threatened, a sea cucumber contracts its body, tears a hole in an interior wall, and shoots a few of these noodles out its anus. The threads immediately stretch when they hit seawater, growing up to 20 times their original length before stiffening. They also become sticky when ...