What are tube feet? Give their function.

Explanation

**Step-by-Step Solution:**

1. **Definition of Tube Feet:**
- Tube feet are small, tubular structures that are part of the water vascular system found in echinoderms, a phylum of marine animals.

2. **Location and Structure:**
- These structures are typically located on the underside of echinoderms, such as starfish and sea urchins. They are connected to a network of canals filled with seawater.

...