Water vasuclar system is found in

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding the Water Vascular System**: The water vascular system is a unique feature found in certain marine organisms. It is primarily responsible for locomotion, feeding, and gas exchange.

2. **Identifying the Group**: This system is exclusive to echinoderms, which are marine animals characterized by their spiny skin and radial symmetry. Common examples of echinoderms include starfish, sea cucumbers, and sea urchins.

3. **Analyzing the Options**: The question provides several options to choose from. We need to determine which of these organisms possess the water vascular system.
- **Option 1: C. penn (Pennatula)** - This organism belongs to the phylum Cnidaria and does not have a water vascular system.
- **Option 2: C. hors (Hippocampus)** - This organism belongs to the phylum Chordata and also does not possess a water vascular system.
- **Option 3: C. anemone** - This organism is another member of the phylum Cnidaria and lacks a water vascular system.
- **Option 4: C cucumber (Sea cucumber)** - This organism belongs to the phylum Echinodermata and is known to possess a water vascular system.

4. **Conclusion**: After analyzing all the options, the only organism that possesses a water vascular system is the sea cucumber, which belongs to the phylum Echinodermata.

**Final Answer**: The water vascular system is found in sea cucumbers (phylum Echinodermata).

---