Ball urchin

Scientific name : Mespilia globulus

Small urchin (4 cm) with banded, thin, pointed spines, separated by 10 naked, velvety blue areas.
Living in the back reef, usually hidden during the day. It covers himself with various items (rubble, detritus).
Some similitude for the colour pattern with Tripneustes gratilla, for the spines with Salmacis belli. The blue velvety areas are the best diagnostic.