Scientific name: Paracentrotus lividus
Urchins are found from just below sea level to depths of 20 meters. It occupies deep, round cavities in soft rocks that it enlarges as it grows. It is herbivorous and feeds on algae, which it sometimes covers with to protect itself from intense light.
They move through the rocks at a speed of 1 meter a day to feed and return to their resting point on the rock.