Water -vascular system is a peculiarity of

Options

A. Porifera
B. Coelenterata
C. Mollusca
D. Echinodermata

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the water vascular system and which group of organisms it is specifically associated with.

2. **Defining Water Vascular System**: The water vascular system is a unique hydraulic system that is primarily involved in locomotion, feeding, and respiration in certain organisms.

3. **Identifying the Phylum**: The water vascular system is exclusively found in the phylum Echinodermata. This phylum includes marine organisms such as starfish, sea urchins, and sea cucumbers.

4. **Characteristics of Echinodermata**: Echinoderms are characterized by their radial symmetry in adults and bilateral symmetry in larvae. They are exclusively marine animals.

5. **Exclusion of Other Phyla**:
- **Phylum Porifera**: This group includes sponges, which do not have a water vascular system; instead, they possess a water canal system.
- **Phylum Cnidaria**: This group includes organisms like jellyfish and corals, which also do not have a water vascular system.
- **Phylum Mollusca**: This group includes animals like snails and clams, which have shells and do not possess a water vascular system.

6. **Conclusion**: Based on the above information, the water vascular system is a peculiarity of the phylum Echinodermata.

**Final Answer**: The water vascular system is a peculiarity of Echinodermata.

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