[2] Paracentrotus lividus is found throughout the Mediterranean Sea and in the eastern Atlantic Ocean from western Scotland and Ireland to the Azores, Canary Islands and Morocco.

It is most common in the western Mediterranean, the coasts of Portugal and the Bay of Biscay, where the water temperature in winter varies between 10 and 15 °C.

Although Cymodocea nodosa is a preferred food item, it is seldom found in meadows of this seagrass, perhaps because the shifting sand substrate does not suit it or because of pressure from predators.

In shallow or exposed waters it can use its mouth and spines to dig into soft rocks to create cavities into which it returns and in which it exactly fits.

[3] Paracentrotus lividus is a generalist browser, eating a range of red, green and brown algae in addition to seagrass.

The barren grounds can persist for years though whether this is due to overgrazing by urchins or prevention of recruitment of multicellular photosynthetic organisms by encrusting algae is unclear.

The gonads are considered a delicacy in Lebanon, France, Italy, Spain, Malta, and parts of Croatia, most notably on the island of Korčula, and are also eaten to a lesser extent in Greece.