Pensil sea urchin with blunt needles
Pensil sea urchin has got dull thick needles. It is not dangerous for us and for fish. All day long the sea urchin hides within a hole in a coral. In the night it feeds with sea plants.
This sea urchin has got very dull tips of its needles. There are sea urchins with more sharp conical needles. There are sea urchins with very sharp thin needles. Don't walk on corals.