Fred Bavendam / Slate Pencil Urchin (Heterocentrotus mammillatus) pair attached to rock wall, Kona, Hawaii

Norbert Wu / Slate Pencil Urchin (Heterocentrotus mammillatus) spines are stony and used for wind chimes, Hawaii

Norbert Wu / Pencil Urchin (Ctenocidaris perrieri) and Brittle Star (Ophionotus victoriae) similar to deep sea species, New Harbor, Antarctica