Water sluices over a rock on the North Kohala coast. The dark circles on the rock are helmet urchins, showing they have very good adhesive qualities.
Water sluices over a rock on the North Kohala coast. The dark circles on the rock are helmet urchins, showing they have very good adhesive qualities.

Red pencil urchins add striking color to the reef, seen here among cauliflower coral and, what I think are, black banded urchins.
To identify this, I used John P. Hoover’s book Hawai‘i’s Sea Creatures: A Guide to Hawai‘i’s Marine Invertebrates. His website is hawaiisfishes.com.


Helmet urchins feed on algae at the water’s edge where they move about on little tube legs. I can’t claim to have witnessed any such activity, but for creatures that apparently just sit there, I find them quite cheerful and entertaining. Perhaps I should get out more.
To identify this, I used John P. Hoover’s book Hawai‘i’s Sea Creatures: A Guide to Hawai‘i’s Marine Invertebrates. His website is hawaiisfishes.com.