Question

Why streamlined bodies and presence of setae is considered as adaptations of earthworm?

Answer 1

Stream-lined body of earthworm:
The earthworm has a cylindrical, elongated and segmented body. This helps them to live in narrow burrows underground and for easy penetration into the soil.
Setae of earthworm:
Each segment on the lower surface of the body has number of bristles called setae. They help the earthworm to move through the soil and provide anchor in the burrows.