August 13, 2019

Shipworms have long been a menace to humankind, sinking ships, undermining piers and even eating their way through Dutch dikes in the mid-1700s. Now, researchers have found the first shipworm that eschews wood for a very different diet: rock. The new shipworm – a thick, white, wormlike creature that can grow to be more than a meter long – lives in freshwater.

The rock-eating shipworm is quite different from its wood-eating counterpart. Really clams, all shipworms have two shrunken shells that have been modified into drill heads. Hundreds of sharp invisible teeth cover the shells in the wood eater, but the rock-eating shipworm has just dozens of thicker, millimeter-sized teeth that scrape away rock.

The rock-eating shipworm does have one big thing in common with its wood-eating counterparts, however: its burrowing may cause harm, in this case by changing a river’s course. But its burrowing does have an upside. The crevices it creates provide great homes for crabs, snails, and fish.

SOURCE: cnn.com, 7/18/19