Common name: Purple sea urchin

General information

The Purple Sea Urchin, Paracentrotus lividus, is a well-known species among marine enthusiasts and researchers due to its striking coloration and ecological importance. This species exhibits a range of colors from purple to brown and even green, with robust spines that can reach up to 3 cm in length. It plays a significant role in shaping the marine environment by grazing on algae, which helps prevent algal overgrowth on reefs.

Care

In the aquarium, Paracentrotus lividus requires a stable environment with plenty of live rock and algae for grazing. They are sensitive to water quality and require consistent levels of salinity, pH, and temperature. It's important to provide them with ample space to move around and access to a variety of algal species to maintain their health.

Reproduction

Purple Sea Urchins reproduce by releasing their gametes into the water column, where external fertilization occurs. In an aquarium setting, this spawning behavior can be induced by changes in water temperature or by simulating the natural increase in photoperiod that occurs during the spring.

Symbiosis

While Paracentrotus lividus does not have any well-known obligate symbiotic relationships, it does contribute to the overall health of the reef ecosystem by controlling algae populations. This, in turn, benefits corals and other invertebrates that compete with algae for space and light.

Habitat

Native to the Mediterranean Sea and the eastern Atlantic Ocean, the Purple Sea Urchin is typically found in shallow waters, often in rocky areas where there is an abundance of algae to feed on. They can be found at depths ranging from the intertidal zone to about 40 meters.