The spines are robust and sharp, black with sometimes a blue-greenish tinge (depending on the light).

They can be recognized thanks to the 5 grey sutures on the upper face, exhibiting distinctive zig-zag pattern.

The juveniles are clearer too (they can be black but also pale brown), and often show strikingly asymmetrical spines, due to their habit to use them for digging hiding holes in soft rocks.

This species shows a remarkably patchy distribution though it can be pretty abundant where they are found.

They can be encountered from the east African coast to the Philippines, on rock and damaged reefs, most often in shallow waters but never too close to wave action.