Urchin pine (Echinometra mathaei)

The Boring Urchin ( Echinometra mathaei ), also known as the Rock Boring Urchin, is a small but remarkably robust sea urchin native to the Indo-Pacific region. Its short but sturdy spines and its ability to burrow into limestone have earned it the nickname "Boring Urchin." Its coloration varies from black to brown among individuals.

His role in the baccalaureate

An efficient algae grazer in confined spaces — its small size allows it to access areas inaccessible to larger sea urchins. Its burrowing behavior in rocks, while spectacular in the wild, is generally less pronounced in aquariums where the rocks are often calcified.

Recommended conditions

• Temperature: 24–27°C
• Salinity: 1.024–1.026
• pH: 7.8–8.4 (normal natural day/night fluctuation in a reef tank)
• Alkalinity: 8–11 dKH — Calcium: 400–450 ppm
• Minimum volume: 100L with solid rocks

Behavior

Primarily nocturnal. It shelters in rocky cavities during the day. Over time, it can burrow into porous limestone. Harmless to corals and fish.