The Life of an Earthworm

By: Collin Mendoza

Lumbricus terrestris

The common earthworms are from the Kingdom Animalia, Phylum Annelida, Class Clitellata, Subclass Oligochaeta, Order Haplotaxida, Familiy Lumbricidae, Genus Lumbricus, Species Terrestris. Earthworms are also invertebrates. Earthworms are about 25 cm on average. Earthworms are cylindrical in shape and divided into multiple segments. Earthworms are also called "nightcrawlers" because they are more active at night than they are during the day.

Reproduction cycle of an earthworm

Earthworms are hermaphrodites. This means that earthworms have both male and female reproduction organs in them. To reproduce, two earthworms slide past each other. As the two earthworms slide past each other, sperm will enter the other earthworm's clitellum, thus fertilizing the earthworm. Soon, the earthworm will have a cocoon grow onto the clitellum. For a cocoon to hatch, the conditions have to be right. A cocoon can wait for years just to have the right conditions to hatch. Once a cocoon hatches, little white earthworms come out and start eating right away. This cycle can repeat in 4-6 weeks due to the short growing time it takes for a premature earthworm to grow into a mature earthworm.

Habitat of an Earthworm

Earthworms are most commonly found in moist, soil areas. Earthworms burrow narrow channels and eat nutrients while they burrow.

Digestive System of an Earthworm

The digestive system of an earthworm consists of the mouth, pharynx, esophagus, crop, gizzard, and intestine. The mouth is covered by strong lips. After the mouth, food is passed down to the pharynx where the food is covered in a mucous membrane. Food moves down into the esophagus where calcium carbonate is added to the mixture. Calcium carbonate is used to neutralize the acids in the body after the food is digested. Food is then stored in the crop. The real digestive process begins in the gizzard. The gizzard mixes food and soil. The walls of the gizzard also add enzymes into the mix to help breakdown the food and soil. The mixture then passes to the intestine where the food is eaten and the wastes then go down throughout the anus and back into the world.
Earthworm Digestive & Circulatory Systems