Hirudinaria is

Options

A. Marine aquatic
B. Terrestrial annelid
C. Endoparasite
D. Ectoparasite

Answer

**Step-by-Step Solution:**

1. **Identify the Organism**: Hirudinaria is a member of the phylum Annelida, commonly known as leeches.

2. **Understand the Characteristics**: Leeches, including Hirudinaria, are sanguivorous, meaning they feed on blood. They can suck blood from various organisms such as fish, frogs, cattle, and humans.

3. **Determine the Type of Parasite**: Since leeches feed on the blood of other organisms externally, they are classified as ectoparasites. Ectoparasites live on the surface of their host rather than inside it.

4. **Examine the Habitat**: Hirudinaria is primarily found in freshwater environments like lakes and ponds. Some species may also inhabit marine environments, but the majority are aquatic. A few species can be found in terrestrial habitats, but they are predominantly aquatic.

5. **Evaluate the Options**:
- **Marine**: Incorrect, as they are primarily freshwater.
- **Aquatic**: Correct, as most leeches live in aquatic environments.
- **Terrestrial**: Incorrect, while some species can be terrestrial, they are not primarily classified as such.
- **Endoparasite**: Incorrect, as they are ectoparasites.

6. **Conclusion**: The correct answer is that Hirudinaria is primarily an aquatic ectoparasite.

**Final Answer**: Hirudinaria is an aquatic ectoparasite.

---