The heartworms that can accumulate within the hearts of dogs and other mammals have a pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong? a. Platyhelminthes b. Annelida c. Arthropoda d. Nematoda

Nematode.

Explanation:

Heartworms belongs to phylum Nematoda, their biological name is Dirofilaria immitis. Their body structure is a tiny thread-like parasite roundworm. Adult heartworms always live in the lung arteries and the heart of the dogs and other mammals, it can spread from one species to another by the mosquito bites. Some characteristics of Nematoda phylum are:

1) Their body structure is triploblastic, bilaterally equal and cylindrical in shape.

2) They show a tissue-level organization.

3) Their body keeps a pouch or pseudocoelom.