The characteristic larva of phylum coelenterata is

Options

A. (a) Planula
B. (b) Cystecierus
C. (c) rhabdiform
D. (d) wriggler

Answer

To answer the question regarding the characteristic larva of phylum Coelenterata, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Identify the Phylum**: The question asks about the characteristic larva of phylum Coelenterata, which is also known as Cnidaria.

2. **Understand the Larval Forms**: In Cnidarians, there are different life stages, including the polyp and medusa forms. The larval stage is crucial for the development of these organisms.

3. **Recognize the Characteristic Larva**: The specific larval form that is characteristic of Coelenterates is known as the "planula."

4. **Describe the Planula**:
- The planula larva is ciliated, meaning it has tiny hair-like structures (cilia) that help in movement.
- It is cylindrical in shape.
- The planula is a free-living larva, which means it does not depend on the adult form for survival during this stage.

5. **Conclusion**: Based on the characteristics mentioned, the correct answer to the question is **A. planula**.

### Final Answer:
The characteristic larva of phylum Coelenterata is **A. planula**.

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