Common name: Gem surgeonfish
General information
The Gem Tang, scientifically known as Zebrasoma gemmatum, is a highly sought-after marine fish in the reefkeeping hobby, prized for its striking appearance and rarity. This species is characterized by its deep black body adorned with a constellation of white spots, which can vary in size and pattern among individuals. The Gem Tang is a member of the surgeonfish family and shares the group's distinctive scalpel-like spine near the tail, which is used for defense.
Due to its rarity and the challenges associated with collecting it from its natural habitat, the Gem Tang commands a premium price in the aquarium trade. It is also known for its robustness and adaptability, making it a prized specimen for experienced aquarists.
Details
- Recommended minimum tank volume
- 300 liter (79 gallons)
- Salinity
- S.G. 1.023 to 1.025
- Temperature
- 24 to 28 °C (75 to 82 °F)
- Acidity
- pH 8.1 to 8.4
- Average size
- 22 cm (9″)
- Care level
- Moderate to difficult Sensitive to water quality.
- Diet
- Herbivore Prefers algae, nori sheets.
- Social
- Solo Territorial, best kept alone.
- Reefsafe
- Yes
- Aggression
- Semi aggresive May be territorial.
- Captive bred
- No
Taxonomy
- KingdomAnimalsAnimalia
- PhylumChordatesChordata
- ClassRay-finned FishesActinopterygii
- OrderPerciformesPerciformes
- FamilySurgeonfishAcanthuridae
- GenusSailfin TangZebrasoma
- SpeciesGem surgeonfishZebrasoma gemmatum (Valenciennes, 1835)
- SynonymsAcanthurus gemmatus Valenciennes, 1835
Care
Gem Tangs require a spacious aquarium with plenty of swimming room and a well-established environment with stable water conditions. They are herbivorous and thrive on a diet rich in marine algae and vegetable matter. Supplementing their diet with high-quality dried seaweed and algae-based pellets or flakes will help maintain their health and coloration.
These fish are generally peaceful but can exhibit territorial behavior, especially towards conspecifics or similar-looking species. It is advisable to introduce them to the aquarium last to minimize aggression. Providing ample hiding places and a complex environment can help reduce stress and territorial disputes.
Reproduction
In the wild, Gem Tangs are pelagic spawners, releasing their eggs and sperm into the water column where fertilization occurs. The larvae are planktonic before settling down and transforming into juveniles. Breeding Gem Tangs in captivity is challenging and rarely achieved by hobbyists, but advances in marine aquaculture may make captive-bred specimens more available in the future.
Habitat
Zebrasoma gemmatum is endemic to the Western Indian Ocean, particularly around the islands of Mauritius and Réunion. They inhabit clear, current-swept outer reef slopes and drop-offs, typically at depths ranging from 10 to 60 meters. In the aquarium, replicating their natural environment with strong water movement and high water quality is essential for their well-being.