Which one of the following is a fresh water sponge ?

Options

A. Sycon
B. Spongilla
C. Euspongia
D. Euplectella

Answer

To solve the question "Which one of the following is a fresh water sponge?" we will analyze the options provided and identify the correct answer step by step.

### Step-by-Step Solution:

1. **Understanding Sponges**:
- Sponges belong to the phylum Porifera. They are primarily aquatic animals and are known for their porous bodies.
- Most sponges are marine, but there are also freshwater species.

2. **Analyzing the Options**:
- **A. Cycle**: This option does not correspond to any known sponge species. It is likely a misrepresentation or typo.
- **B. Spongilla**: This is a known genus of freshwater sponges.
- **C. U. Spongilla**: This seems to be a repetition or misrepresentation of Spongilla.
- **D. U. Plagdella**: This option does not correspond to any recognized sponge species.

3. **Identifying Freshwater Sponges**:
- Among the options, Spongilla is recognized as a freshwater sponge. It is commonly found in ponds and streams.

4. **Conclusion**:
- Based on the analysis, the correct answer to the question is **B. Spongilla**.

### Final Answer:
The freshwater sponge among the given options is **B. Spongilla**.