A dark short-spined urchin that grinds a socket into rock and sits in it, in the surge zone where the water is roughest.
Test to about 8 cm. An elliptical test, black to deep brownish-red and redder on top, with moderately short spines that have broad bases and pointed tips.
The other Caribbean Echinometra has a pale ring at the base of each spine; this one’s spines are uniformly dark.
Usually around two metres and occasionally to forty-five, in surge on rock and reef. It grinds a hemispherical socket into the rock with its teeth and defends it, which makes it a significant eroder of reef limestone.
One thing worth recording. After both the 1983 and the 2022 long-spined urchin die-offs, this species did not expand to take over the grazing that was lost.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.