It has numerous long, thin, sharp spines. Usually all black but young have back and white banded spines. Long-spined urchin is a keystone species in Caribbean coral reef controlling the abundance of algae on them. It suffered a massive die-off by the beginning of the 1980s causing a shift baseline of Caribbean coral reef from corals-dominated to algae-dominated ones. Long-spined urchin is recovering slowly since then. Jardines de la Reina is one of the few places in the Caribbean showing a strong recovery of Long-spined urchin population. It is included in the Appendix II of Resolution 161/11.