How earthworm moves

Describe how earthworm moves : [ 5 marks]

v an invertebrate which has a hydrostatic skeleton.

v Body wall has longitudinal and circular muscles

v These muscles act antagonistically to cause movement

v Contractions of circular muscles cause the segments to extend while longitudinal muscles relax //

v Conversely the contractions of the longitudinal muscles cause segments to shorten.

v Locomotion takes place when the chaetae secure shortened segments in the posterior to the ground while //

v The anterior segments extend owing to contractions of the circular muscles.

v Fluid in the body cavity helps the earthworm to move.

**Note:

1.Any of the five points above for the maximum marks.

2.Written in bold are the Key sentences.