Postcard from the Reef – Banded Urchin A young banded urchin (Echinothrix calamaris) embedded in a cave wall at 25ft depth at Holoholokai Related Posts Banded Urchin Postcard from the Reef - The Horn of Urchin Death Postcard from the Reef - Fine-Spined Urchin Share this:TweetWhatsAppEmail Author: Andrew An electrical engineer, amateur astronomer, and diver, living and working on the island of HawaiĘ»i. View all posts by Andrew