Asexual reproduction through formation of gemmule occurs in

Options

A. Ascidia
B. Hydra
C. Planaria
D. Spongilla.

Answer

To answer the question "Asexual reproduction through formation of gemmule occurs in:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Gemmules**: Gemmules are a form of asexual reproduction. They are internal buds that can develop into new organisms. This process is primarily observed in certain types of sponges.

2. **Identifying the Organisms**: The options provided are:
- A. Ascidia
- B. Hydra
- C. Planaria
- D. Spondyla

3. **Analyzing Each Option**:
- **Ascidia**: This organism is a type of tunicate and reproduces sexually, not through gemmules.
- **Hydra**: Hydra reproduces asexually through budding but does not form gemmules.
- **Planaria**: Planaria can reproduce asexually through regeneration but does not form gemmules.
- **Spondyla**: This is a freshwater sponge known for reproducing asexually through the formation of gemmules.

4. **Conclusion**: Based on the analysis, the organism that reproduces asexually through the formation of gemmules is Spondyla.

5. **Final Answer**: The correct answer is **D. Spondyla**.