Movement

- Hydrostatic Skeleton: supports the segments 
                  * Muscles contract around the skeleton in order to move

- Setae: external bristles, has one pair on each segment, provide traction to the annelid

- Movement of an Earthworm   

    1.) Rear anchors
                * sinking setae into the ground

    2.) Elongation:
                * contracting the circular muscles in the front

                                     3.) Front anchors: 
                                                  * front setae sink in, rear setae are released

                                     4.) Pull:
                                                  * circular muscles relax, longitudinal muscles contract, pulling rear

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