GENERAL HISTOLOGY

Detailed explanation-1: -Earthworms travel underground by means of waves of muscular contractions which alternately shorten and lengthen the body (peristalsis). The shortened part is anchored to the surrounding soil by tiny clawlike bristles (setae) set along its segmented length.

Detailed explanation-2: -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. These hairs make it difficult to pull a worm straight from the ground. Setae in oligochaetes (a group including earthworms) are largely composed of chitin.

Detailed explanation-3: -Bristles, called setae, are located on each segment of the earthworm’s body. They prevent the earthworm from slipping backwards.

Detailed explanation-4: -The basic features of locomotion in annelids are most easily observed in the earthworm because it lacks appendages and parapodia. Movement involves extending the body, anchoring it to a surface with setae, and contracting body muscles.

Detailed explanation-5: -Annelids are heterotrophic. They are metamerically segmented invertebrates. They have a well developed complete digestive system. They feed on soil, small invertebrates or dead and decaying organic matter.