How do annelids locomote?
Flexi Says:
Non-sedentary annelids have several means of locomotion. Aquatic polychaetes can use their paddle-shaped parapodia to swim. Longitudinal muscles that run along the body wall from the front to the back are surrounded by a sheath of circular muscles. Annelids crawl or burrow by combining the actions of these muscles and the bristles, or setae, on the outside of the body. The organism first extends forward and then anchors the front end of the body to a solid surface using the bristles. With the front of the body immobilized, the worm contracts muscles to bring the rear end closer to the front end. The front end is then released and extended forward again while the rear end becomes anchored so that it does not slip backward as the body extends forward.