Common name: Reef Urchin

General Information

The Reef Urchin, scientifically known as Echinometra viridis, is a fascinating addition to marine aquariums, known for its role in maintaining algae levels. This species is characterized by its dark brown, often black body and brown spines, which can sometimes have a orange tint. It is a common sight in the Caribbean and is appreciated by aquarists for its algae-eating habits, which help keep tanks clean.

In the wild, these urchins play a crucial role in the ecosystem by controlling algae growth, which can otherwise smother corals and disrupt reef health. In captivity, they serve a similar purpose, making them a valuable addition to any reef tank.

Care

Reef Urchins are relatively easy to care for, making them suitable for aquarists of all levels. They require a stable environment with plenty of live rock to graze on. A well-established aquarium with a mature biofilm will provide them with the necessary nutrients.

These urchins are best kept in tanks with at least 100 liters (26 gallons) of water. They require stable water parameters, particularly salinity and pH, to thrive. Providing ample live rock not only offers grazing surfaces but also shelters and hiding spots, which are important for their well-being.

Diet and Feeding

Reef Urchins are primarily herbivores, feeding on algae and biofilm. In captivity, they will graze on algae growing on rocks and tank surfaces. It's important to ensure that there is enough algae available for them to eat. If algae levels are low, supplemental feeding with dried seaweed or algae wafers can be beneficial.

Behavior and Compatibility

Reef Urchins are generally peaceful and can coexist with a variety of tank mates. However, their spines can pose a risk to fish or invertebrates that get too close. They are slow-moving and spend most of their time grazing on surfaces.

While not aggressive, they can inadvertently knock over unsecured corals or rocks, so ensure that tank decorations are stable.

Health and Common Issues

Reef Urchins are hardy creatures but can be sensitive to sudden changes in water conditions. Maintaining stable water parameters and regular monitoring of salinity, pH, and temperature are crucial. They are generally resistant to disease but can suffer from poor health if algae levels are insufficient.

When selecting a Reef Urchin, look for active individuals with intact spines and a healthy appetite for algae. Avoid urchins with damaged spines or those that appear lethargic.

Habitat

Echinometra viridis is naturally found in the Caribbean Sea, thriving in coral reefs and rocky substrates. They prefer shallow waters where they can easily graze on algae. In captivity, replicating these conditions with plenty of live rock and stable water parameters will help them thrive.