Encyclopaedia
InvertebrateMarineIntermediate
©AI Generated·Proprietary
Green Rock Urchin
Echinometra viridis
An active Caribbean sea urchin displaying thin, greenish spines. It acts as a superb algae grazer, though it should be housed cautiously in reef setups.
Class:Echinoidea
Order:Camarodonta
Family:Echinometridae
Genus:Echinometra
Species:Echinometra viridis
Share
Check out Green Rock Urchin on Atlarium
Water Temperature
24 - 27 °C
pH Value
8.1 - 8.4
Water type
Marine
Adult size
10 cm
Minimum group
>= 1
KH
8 - 12 dKH
Species description
Geographical Origin and Habitat: Common in the tropical waters of the Caribbean, Gulf of Mexico, and Florida, where it colonizes shallow rocky reefs and seagrass beds.
Taxonomy: Belongs to the class Echinoidea. Features a rounded calcareous test covered with sharp, mobile spines that are circular in cross-section.
Social Behavior: Solitary and nocturnal. Stays wedged in rocky crevices during daylight hours to avoid predators and emerges at night to forage. Predominantly nocturnal and solitary creature. It wedges itself into rocky crevices during the day and emerges at night to graze on benthic algae.
Coloration and Sexual Dimorphism: Spines are green or reddish-green, often with lighter rings near the base. No visible external dimorphism between males and females. The spines exhibit a signature bright green coloration, often with red or purple tips. No external sexual dimorphism is visible.
Care, breeding and tankmates
Tank Setup: Safe with most fish and large invertebrates. Use caution with small corals or frags, as the urchin may knock them over or graze on them. Requires a mature marine aquarium with plenty of stable rockwork, as this urchin can knock over loose corals and unsecured rocks during its movement.
Diet and Feeding: Herbivore. Primarily grazes on film algae, hair algae, and macroalgae. Supplement with dried seaweed (nori) if natural algae levels are low. Herbivorous. Feeds mainly on nuisance algae and detritus. If natural algae levels are low, supplement their diet with dried nori seaweed sheets.
Water Quality: Requires clean, stable marine parameters: temperature 24-27°C, pH 8.1-8.4, SG 1.023-1.026. Keep nitrates below 10 ppm. Keep water parameters stable: temperature 22-27°C, pH 8.1-8.4, specific gravity 1.022-1.025. Calcium and magnesium levels must be kept high for spine health.
Compatibility and Tankmates: Herbivore. Primarily grazes on film algae, hair algae, and macroalgae. Supplement with dried seaweed (nori) if natural algae levels are low. Safe with most reef fish and invertebrates. Do not house with dedicated urchin predators such as triggerfish, large wrasses, or puffers.
Aquarium Breeding: Safe with most fish and large invertebrates. Use caution with small corals or frags, as the urchin may knock them over or graze on them. Spawning in home aquariums is highly unlikely. In nature, gametes are released into the water column, followed by a delicate planktonic larval stage.
Risks and Diseases: Highly sensitive to copper treatments and sudden salinity drops. Dropping spines is a major warning sign of stress or poor water parameters. Extremely sensitive to copper treatments (which are lethal) and sudden drops in salinity. Always use a drip method for proper acclimation.
Geographic Origin and Distribution
Common in the tropical waters of the Caribbean, Gulf of Mexico, and Florida, where it colonizes shallow rocky reefs and seagrass beds.
Origin
Tropical oceans and reefsCentral America and CaribbeanNorth America
Invertebrate profile
- Diet
- No verified data available
- Ecological role
- No verified data available
- Life expectancy
- No verified data available
- Adult size
- 10 cm
- Jump risk
- No verified data available
- Shock sensitivity
- No verified data available
- Calcium and minerals
- No verified data available
- Molting
- No verified data available
- Reproduction
- No verified data available
- Compatibility & tankmates
- No verified data available
The catalog's scalar value is 10 cm. The MOBS marine organism body-size database source reports a maximum adult measurement of 10 cm for this species, recorded as the dataset's reported length dimension. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Recommendations grouped by close relatives, companion choices, and similar care.
