The Life of a Earthworm

Earthworm Dissection Vu-PAP Bio - 3

The Earthworm (Lumbricus terrestris)

The earthworm, (Lumbricus terrestris) is an order of roundworm. The earthworm belongs under kingdom Animalia, phylum Annelida, and class Ogliochaeta. Certian characteristics include a life of burrowing through soil, the mucus on the skin of the earthworm, and the muscular pharynx, which allows for movement in the soil. Earthworms are classified as decomposers, so they break down dead organic matter in the soil. The earthworm is a hermaphrodite, meaning that the earthworm has both male and female sex organs which are the cilteilum and the testes.

Today's objectives

The student will observe the external and internal structure of the earthworm. The student will focus on the organs, functions, and the circulatory and digestive systems of the earthworm.

Dissection of the earthworm

Body system spotlight: Circulatory

The earthworm's circulatory system in closed, which means that the blood cannot leave the blood vessels. The earthworm has 5 main blood vessels: the ventral (bottom) vessel, the dorsal (top) vessel, the subneural vessel, and two lateroneuron vessels, which are located on eithier side of the earthworm's nerve cord. When oxygen enters the body, the dorsal vessel takes in the oxygen to the hearts through the esophagus. Then the oxygen is pumped to the ventral blood vessel where blood is pumped to the organs that need oxygen. To complete this "loop" the small blood vessel sends the blood from the ventral blood vessel to the dorsal blood vessel.