The sea urchin can be found all across the ocean floors. They are rarely going to be found in cold regions. They are most likely found in coral reefs. Sea urchins have a round shaped body with long spines that come off it's body. They use the spines for protection, to get food, and to move around. On the feet of sea urchin, they have suckers that help them move around. Lateral movement happens by paired muscles in the foot and extension and retraction by muscles behind each tube foot.