Which is a fresh water cnidarian ?

Options

A. Hydra
B. Spongilla
C. Dugesia
D. None of the above.

Answer

**Step-by-Step Solution:**

1. **Identify the Options**: The question provides four options to choose from:
- A) Hydra
- B) Spongilla
- C) Euglena
- D) None of the above

2. **Analyze Each Option**:
- **Option A: Hydra**: Hydra is a well-known freshwater cnidarian. It is part of the phylum Cnidaria and is commonly found in freshwater environments. Additionally, it has specialized cells called cnidocytes that help in capturing prey.

- **Option B: Spongilla**: Spongilla is a freshwater organism, but it belongs to the phylum Porifera (sponges), not Cnidaria. Therefore, this option is incorrect.

- **Option C: Euglena**: Euglena is a genus of single-celled organisms that can be found in freshwater, but it is a protist, not a cnidarian. Thus, this option is also incorrect.

- **Option D: None of the above**: Since we have identified that Hydra is a freshwater cnidarian, this option is incorrect.

3. **Conclusion**: Based on the analysis, the only correct answer is **Option A: Hydra**, as it is the only freshwater cnidarian listed among the options.

**Final Answer**: The freshwater cnidarian is **Hydra**.

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