Bootlace Worm

August 1, 2011
By Damond Benningfield

The longest creature in the oceans is no giant. Although it’s longer than any shark, whale, squid, or other denizen of the marine world, you could step right over it on the beach -- several times, in fact -- without even noticing it. That’s because while it could stretch half the length of a football field, it’s not much thicker than a strand of spaghetti.

A preserved bootlace worm. Credit: Wikipedia

The bootlace worm is one of several hundred species of flat worms that belong to a group known as Nemertea. Most inhabit the oceans, while a few live in fresh water .

Most of them are only a few inches to a few feet long. But the bootlace just keeps going and going and going. It can grow to 30 feet or longer, and the longest stretch more than 150 feet. They’re found in the waters around western Europe. They’re often found onshore, wiggling beneath boulders and atop the sand.

Bootlace worms feed through a tube known as a proboscis. When a bootlace finds prey, it uses strong muscles to squeeze out the proboscis. A hook on the end of it grabs the prey.

The bootlace also produces a sticky mucus that basically glues the worm to its meal. It then ties itself around the prey like a ribbon on a birthday package. It can then pull the prey in through its mouth, just below the proboscis, and swallow it whole. So while the bootlace worm is less ferocious looking than some other long ocean dwellers, it survives in the same way -- by gobbling up the smaller ones.