Common name: Diadema urchin

General information

The Diadema Urchin, scientifically known as Echinothrix diadema, is a striking marine invertebrate commonly found in reef aquariums. It is easily recognizable by its long, black spines that can exhibit blue or white banded patterns. This urchin plays a significant role in controlling algae growth, making it a beneficial addition to a reef tank.

Care

Diadema Urchins require a tank with plenty of live rock and a stable environment to thrive. They are sensitive to water quality and require consistent levels of calcium for their spines and exoskeleton. It's important to ensure that the aquarium does not have aggressive fish that may attack the urchin's spines.

Reproduction

In the wild, Diadema Urchins reproduce by releasing gametes into the water column, a process known as broadcast spawning. In captivity, breeding is less common but can occur in well-established systems with multiple individuals.

Symbiosis

While not known for specific symbiotic relationships like clownfish and anemones, Diadema Urchins often provide shelter for small fish and invertebrates among their spines, inadvertently offering protection from predators.

Habitat

Echinothrix diadema is typically found in tropical coral reefs, often in crevices or under rocks during the day. At night, they become more active and roam the reef in search of algae to graze on. They are distributed across the Indo-Pacific region, from the Red Sea to the waters of Hawaii and the Tuamotu Archipelago.