An illustration of an earthworm. The basic body plan of an earthworm is a tube, the digestive system, within a tube, the muscular outer body. The body is annular, formed of segments that are most specialized in the anterior. Earthworms have a simple circulatory system. They have two main blood vessels that extend through the length of their body: a ventral blood vessel which leads the blood to the posterior end, and a dorsal blood vessel which leads to the anterior end. Most earthworms are decomposers feeding on undecayed leaf and other plant matter, others are more geophagous.

Earthworm

An illustration of an earthworm. The basic body plan of an earthworm is a tube, the digestive system,…

An illustration of an earthworm escaping a cocoon.

Earthworm Escaping Cocoon

An illustration of an earthworm escaping a cocoon.