Earthworms, invertebrates belonging to the Annelida phylum, are commonly found in soils around the world. They play a crucial role in enhancing soil fertility as they feed on dead organic matter. The most common earthworms found in India are the Pheritima and Lumbricus species.
Earthworms are hermaphrodites with a long, cylindrical, and segmented body structure. Their digestive system consists of an alimentary canal running from the mouth to the anus, along with various glands.
Below are the primary characteristics of an earthworm:
The digestive system of an earthworm comprises an alimentary canal that runs along the length of the body from the mouth to the anus, along with various glands.
The alimentary canal is a long, straight structure that runs from the first to the last segment of the body.
| Parts of the alimentary canal | No. of the segment in the body |
| Mouth | 1 |
| Buccal Cavity | 2-3 |
| Pharynx | 3-4 |
| Oesophagus | 5-7 |
| Gizzard | 8-9 |
| Stomach | 9-14 |
| Intestine | 15-last |
| Anus | last |
Earthworms feed on the dead and decaying organic matter present in the soil. Their digestion is an extracellular process, which means the food is broken down outside the cells.
Additional Resources:
What is typhlosole?
Typhlosole is the large internal median fold of the dorsal wall of the intestine forming a longitudinal ridge, which is present after the 26th segment, except the last 23rd-25th segments. Typhlosole increases the area of absorption in the intestine.
What are the enzymes present in an earthworm?
The digestion in earthworms is an extracellular process. The food is broken outside the cell with the help of some enzymes. Enzymes such as protease, amylase, lipase, cellulase and chitinase help in this digestion process.