Which of the following animals belongs to phylum Coelentarata?

Options

A. Sea horse
B. Sea hare
C. Sea pen
D. Sea cucumber

Answer

To determine which of the following animals belongs to the phylum Coelenterata, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand the Phylum Coelenterata**:
- Coelenterata, also known as Cnidaria, includes animals like jellyfish, corals, and sea anemones. They are characterized by their radial symmetry and the presence of specialized cells called cnidocytes.

2. **Examine the Options**:
- We have four options to evaluate: seahorse, seahair, seapen, and sea cucumber.

3. **Option 1: Seahorse**:
- The scientific name for seahorse is *Hippocampus*. Seahorses belong to the phylum Chordata, not Coelenterata.
- **Conclusion**: Seahorse does not belong to Coelenterata.

4. **Option 2: Seahair**:
- The scientific name for seahair is *Aplysiomorpha*. Seahair belongs to the phylum Mollusca.
- **Conclusion**: Seahair does not belong to Coelenterata.

5. **Option 3: Seapen**:
- Seapen refers to organisms in the order Penatulaceae, which are indeed part of the phylum Coelenterata (Cnidaria).
- **Conclusion**: Seapen belongs to Coelenterata.

6. **Option 4: Sea Cucumber**:
- The scientific name for sea cucumber is *Holothuroidea*. Sea cucumbers belong to the phylum Echinodermata.
- **Conclusion**: Sea cucumber does not belong to Coelenterata.

7. **Final Answer**:
- After evaluating all the options, the only animal that belongs to the phylum Coelenterata is **seapen**.