How do earthworms breathe?

Explanation

1. The earthworm has no special respiratory organs like lungs or gills. Respiration takes place through the body wall.
2. The outer surface of the skin is richly supplied with blood capillaries which aid in the diffusion of gases.
3. Oxygen diffuses through the skin into the blood while carbon dioxide from the blood diffuses out.
4. The skin is kept moist by mucous and coelomic fluid and facilitates exchange of gases.