Gem Tang
Gem Tang (Zebrasoma gemmatum)
The Gem Tang is widely regarded as one of the most striking and sought-after surgeonfish in the marine aquarium hobby. Native to the deeper reefs of the Western Indian Ocean, this species is prized for its velvety black body adorned with brilliant white spots and a subtle yellow accent near the tail. Its rarity, beauty, and engaging personality make it a true centerpiece fish for advanced reef aquariums.
Despite its premium status, the Gem Tang can adapt well to captivity when provided with appropriate space, stable water conditions, and a nutrient-rich diet.
Care Level
Moderate to Advanced
Temperament
Semi-aggressive
Generally peaceful toward non-tang species. Can be territorial toward other tangs, especially those with a similar body shape. Best housed singly unless introduced carefully in very large systems.
Reef Compatibility
Reef Safe
Does not harm corals or invertebrates.
Minimum Tank Size
180 gallons recommended
Larger systems are strongly encouraged to allow for ample swimming space and reduced territorial behavior.
Diet
Herbivore / Omnivore
A varied diet is essential for long-term health:
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Dried seaweed (nori) offered daily
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High-quality herbivore pellets and flakes
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Frozen foods such as mysis shrimp and spirulina blends
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Occasional fresh macroalgae
Frequent feedings help reduce aggression and support immune health.
Water Parameters
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Temperature: 74–78°F
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Salinity: 1.024–1.026
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pH: 8.1–8.4
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Alkalinity: 8–10 dKH
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Nitrate: <20 ppm
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Phosphate: <0.1 ppm
Stable, well-oxygenated water with strong flow is essential.
Behavior & Compatibility
The Gem Tang is active, intelligent, and constantly grazing throughout the day. It benefits from live rock structures that provide both grazing surfaces and hiding areas. Introducing this fish as one of the last additions to the tank can help minimize territorial disputes.
Additional Notes
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Quarantine is highly recommended prior to display introduction
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Sensitive to poor water quality and sudden parameter changes
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Requires excellent filtration and consistent maintenance
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Known to be susceptible to ich if stressed
