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
Real Life Disection
This is the internal anatomy of the Earthworm
Internal Anatomy - Labeled
The internal anatomy includes the crop, seminal vesicles, pharynx, mouth cavity, seminal receptacles, aortic arches, the ganglia.
External Anatomy - Labeled
The external anatomy includes the mouth, segment, setae, sperm grooves, anterior end, sperm duct openings, clitellum, and at the very end of the worm is the anus.
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.