Hirudinaria differs from Wuchereria, in that it:

Shows metamerism

Metamerism refers to the segmentation of the body into distinct repeating units. This characteristic is observed in Hirudinaria, but not in Wuchereria.

Explanation:

Metamerism in Hirudinaria:
Hirudinaria, commonly known as the medicinal leech, belongs to the phylum Annelida. Annelids are characterized by their segmented body, which exhibits metamerism. Each segment, or metamere, contains a set of organs and structures that are repeated throughout the body. This segmentation allows for flexibility and efficient movement in the leech.

No metamerism in Wuchereria:
Wuchereria, on the other hand, belongs to the phylum Nematoda. Nematodes, also known as roundworms, do not exhibit metamerism. Their body is elongated and cylindrical, lacking the distinct segmented structure seen in annelids. Instead, the body of a nematode is divided into regions such as the head, neck, and tail, but these regions do not show the repetition of identical segments found in annelids.

Other differences between Hirudinaria and Wuchereria:
Although metamerism is a key difference between Hirudinaria and Wuchereria, there are other notable distinctions as well:

Hirudinaria:
- Is a parasite: Hirudinaria is a blood-feeding parasite that attaches itself to the host's skin and feeds on its blood.
- Has separate oral and anal openings: Hirudinaria has a distinct mouth and anus, allowing for the intake of blood and excretion of waste materials.
- Belongs to the class Hirudinea: Hirudinea is a class within the phylum Annelida, which includes leeches.
- Possesses a muscular sucker: Hirudinaria has a muscular sucker at the anterior end, which helps it attach to the host.

Wuchereria:
- Is also a parasite: Wuchereria is a parasitic nematode that causes lymphatic filariasis in humans.
- Does not show metamerism: As mentioned earlier, nematodes like Wuchereria do not exhibit the segmented structure seen in annelids.
- Belongs to the class Secernentea: Secernentea is a class within the phylum Nematoda, which includes many parasitic and free-living roundworms.
- Has a tubular digestive system: Wuchereria possesses a tubular digestive system, with a mouth at the anterior end and an anus at the posterior end.

In summary, Hirudinaria differs from Wuchereria in that it shows metamerism, while Wuchereria does not. Additionally, they differ in terms of their classification, feeding mechanisms, and body structures.

Wuchereria is unsegmented. Both animals have tube within tube plan, are parasites and are protostomes.