Outside Earthworm

Setae

Each segment has a number of bristly hairs that earthworms use to help them move. Sometimes, if you run your fingers on the underside (ventral) of the earthworm, you can feel the setae.

Anus

The posterior (last) segment of the earthworm’s body. The anus excretes wastes (worm casts).

Dorsal

The top of the earthworm running from the anterior to the posterior.

Ventral

The underside of the earthworm running from the anterior to the posterior. You can locate the ventral section by feeling for the setae.

Prostomium and Mouth

The first segment on the earthworm’s anterior holds the prostomium and mouth. The prostomium, resembling a lip, is in front of the mouth. Earthworms use their pharynx to pull food into their mouths.

Clitellum

The glandular ring or saddle found on mature earthworms. After mating, the clitellum secretes a cocoon of eggs.

Segment

The body is divided into segments. These resemble rings. Large earthworms are made up of hundreds of segments.

Anterior

The ‘head’ or front of the earthworm is called its anterior.

Skin

Earthworms breathe and lose moisture through the skin. Light-sensitive cells are scattered in their skin. They give skin the ability to detect light and changes in light intensity. Skin cells are also sensitive to touch and chemicals.