Earthworm

Earthworm Dissection - Vu PAP Bio pd. 3

Lumbricus terrestris

Lumbricus terrestris, also known as the earthworm, is a member of the phylum Annelida. It has a long, slender body that helps it move through the soil, which is its natural habitat. It also has a mucus coating that aids in oxygen passing through the earthworm's skin. Predators include snakes, birds, rodents, and insects. The earthworm gets the energy it needs by sucking on soil in its path, extracting the nutrients. This also helps the worm move throughout the soil. Niches feed on organic matter and fertilize the soil.

Objective

You will learn about the internal and external anatomy of the earthworm. You will also learn about the digestive system of the earthworm.
Earthworm Anatomy

The Digestive System

The digestive system of the earthworm includes the mouth, esophagus, pharynx, crop, gizzard, and intestine. After the soil enters the mouth it passes through the esophagus which has glands that release calcium carbonate to rid the body of extra calcium. The food then moves to the the crop and then to the gizzard. The gizzard uses sand and tiny stones that the worm ingested to grind the food down completely. The food then moves on to the intestines. The function of the digestive system is to ingest, digest, and absorb food from the soil that the earthworm eats.