This person might look like they’re holding a piece of poo. But it’s really an animal called a dragonfish sea cucumber—and, unfortunately, it just happens to look a lot like poop! The dragonfish sea cucumber’s bumpy brown skin may seem revolting, but it’s part of an important adaptation that helps the animal survive.
Dragonfish sea cucumbers are invertebrates—animals without backbones—that live in reefs in the Pacific Ocean. These squishy creatures would make an easy snack for a predator, like a crab. But the sea cucumbers have a way to defend themselves: They shed their skin to make a surprise getaway.
The sea cucumber’s skin contains tiny fibers of collagen—a connective tissue. If attacked, the sea cucumber will link together these fibers, turning its skin rigid. “Dragonfish sea cucumbers can easily make their skin turn from soft to hard when touched,” says Eizadora Yu. She’s a biochemist at the University of the Philippines who studies the chemical properties of living things. Then the sea cucumber’s insides detach from the hardened skin, and the animal slips out of it. The creature grows new skin in a few weeks.
Recently, Yu and her team analyzed compounds found in the animals’ bodies. Now the scientists are studying the role these compounds play in the sea cucumbers’ unique defense. So far, they’ve found some compounds that may aid in tissue regeneration, or regrowth. Others may even have anticancer properties. So although people might be put off by this little sea creature’s appearance, the animal could help make medicines to benefit human health, says Yu.