to worm locomotion

To a worm, digging through the mud isn't as tough as it seems.

Studying Nereis virens worms moving through gelatin, University of Maine researchers found that the burrowing creatures make cracks ahead of themselves in the muddy sediment. A study in a recent edition of the journal Nature indicates that creating these cracks eases a worm's work load to move through mud.

The worms can form themselves into a wedge shape while alternating between anchoring and burrowing activities, researchers said. While in the hole, the worm turns its pharynx outward to create pressure on the walls of the burrow to extend the crack before retracting the pharynx and moving forward.

This study may also answer questions about how other wedge-shaped animals, including clams, move through muddy environments.

- Greg Lavine