Which direction do the setae point on an earthworm? The earthworm uses its setae to anchor the front of its body in the soil. Now the longitudinal muscles contract and the earthworm becomes shorter and wider or it bends from one side to the other, pulling the body forward.

What is the role of setae?

Annelid setae are stiff bristles present on the body. They help, for example, earthworms to attach to the surface and prevent backsliding during peristaltic motion. ... In some cases, setae are modified into scale like structures. Setae on the legs of krill and other small crustaceans help them to gather phytoplankton.

How does the setae help the earthworm move?

An earthworm moves using circular and longitudinal muscles, as well as bristles called setae. The earthworm can push the setae out of its body to grab the soil around it. To move forward, the worm uses its setae to anchor the front of its body and contracts the longitudinal muscles to shorten its body.