In this article we will discuss about the structure of Earthworm (Pheretima) with the help of a diagram.
1. It is commonly known as earthworm and is terrestrial and burrowing in habit.
2. Body bilaterally symmetrical, triploblastic and metamerically segmented.
3. No distinct head or appendage but a distinct prostomium is present.
4. Clitellumis present in segments 14-16.
5. Single female opening is present in 14th segment, paired male openings in 18th segment and paired genital papillae in the 17th and 19th segment.
6. Anus terminal. The setae are buried in the body-wall all over the surface.
7. Hermaphrodite and reproduction is sexual and is followed by a cocoon formation.
8. Coelom distinct, spacious and coelomic fluid contains coelomic corpuscles.