Rock boring urchins have cream-colored spikes. When you look between the spikes, you can see extending purple tube feet. They can be found in mid-Honshu to Kyushu.  The diameter of the shell can grow up to be 4 to 5 cm in diameter.

You can find many of them in the Dolphin Waterway outside of the aquarium as well.  Our staff usually dives into the ocean and captures them to display them in the touch pool. These sea urchins are not eaten.