Haemocyanin pigment is found in

Options

A. Insecta
B. Annelida
C. Nematoda
D. Crustacea

Answer

**Step-by-Step Solution:**

1. **Understanding Hemocyanin**: Hemocyanin is a respiratory pigment that contains copper. It is important for the transport of oxygen in certain organisms.

2. **Identifying Organisms with Hemocyanin**: Hemocyanin is primarily found in certain groups of animals, particularly in mollusks (like bivalves and gastropods) and arthropods (such as crustaceans and some arachnids).

3. **Analyzing the Options**: The question provides four options:
- Option A: Insecta
- Option B: Annelida
- Option C: Nematoda
- Option D: Crustacea

4. **Determining the Correct Answer**:
- **Insecta**: Insects primarily use hemoglobin, not hemocyanin.
- **Annelida**: Some annelids may have hemoglobin, but not hemocyanin.
- **Nematoda**: Nematodes do not utilize hemocyanin.
- **Crustacea**: Crustaceans, which are a class of arthropods, do contain hemocyanin as their respiratory pigment.

5. **Conclusion**: Based on the analysis, the correct answer is **Option D: Crustacea**.

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