From the Bishop Museum: "The several sea urchin spine ki‘i held at Bishop Museum are brilliantly carved images that were found in 1913 at a koa (fishing shrine) on Kaho‘olawe." http://www.hawaiialive.org/realms.php?sub=Kai+Akea&treasure=373&offset=0
All critters needs a way to defend themselves, so why not put it all out there, with a splash of color to boot? That's what Heterocentrotus mammillatus, or the red slate pencil urchin does, star of today's creature feature. Thick, blunt spines cover its test (the rigid, calcium carbonate structure enclosing the internal organs) and are attached in a ball and socket manner, allowing them to move in any direction. Turns out that the red color rubs off easily, and so the spines were used like pencils or chalk, thus their name. A small red shrimp, Levicaris mammilata, may be found among the spines as well, blending in magnificently. The spines help the urchin to wedge itself into small crevices, which is typically where you'll spot them during the day. At night they're more mobile, using their spines and tube feet to traverse the reef. The tube feet radiate out in five rows, and the urchins use muscles to force water in and out of them, alternately extending and then relaxing the feet in order to move. The mouth is located at the bottom, with five "teeth" and a modified tongue used for scraping and eating algae, it's primary food. These urchins are sensitive to light, as well as touch, and have a sensory receptor that they use to keep themselves upright. Good thing, as some predators try to knock them over to get at the softer bits. I bet that sends a shiver down their spines.
welcomes you to visit with the all the wonderful flora and fauna that we share this lovely aina with.