To which phylum do earthworm and leech belong ?
The correct answer and explanation is:
Earthworms and leeches both belong to the phylum Annelida.
Annelids are segmented worms, meaning their bodies are divided into repetitive segments that are externally and internally visible. This segmentation is a hallmark characteristic of the phylum. Annelids are coelomates, meaning they have a body cavity (coelom) that is completely lined by tissue derived from mesoderm. This feature provides structural support and allows for the development of more complex internal organs.
The phylum Annelida is divided into three main classes: Oligochaeta, Hirudinea, and Polychaeta.
- Earthworms belong to the class Oligochaeta. These worms are primarily terrestrial and are well-known for their role in soil aeration and organic matter breakdown. Earthworms are hermaphroditic, meaning they possess both male and female reproductive organs, and they usually reproduce through a process involving mutual fertilization. Their segmented bodies are equipped with bristles called setae, which help with movement and burrowing through soil.
- Leeches belong to the class Hirudinea. Unlike earthworms, leeches are often aquatic, though some species can be terrestrial. They are well known for their ability to feed on blood. Most leeches have specialized suckers at both ends of their bodies, which allow them to attach to hosts. While many leeches are parasitic, others are predatory or detritivorous. Leeches lack the bristles found in other annelids and have a more flattened body structure, which aids in their locomotion.
In summary, earthworms and leeches are both members of the phylum Annelida, which includes organisms with segmented bodies, a coelom, and specialized structures for movement, feeding, and reproduction.