Gem Tang (Zebrasoma Gemmatum)

The Gem Tang is one of the most prized and sought-after marine fish in the aquarium hobby due to its stunning appearance and rarity. Known for its deep black body speckled with white or blue dots, this fish has a gem-like sparkle, which gives it its name. Native to the waters of the Western Indian Ocean, particularly around Mauritius, this tang adds a touch of elegance to any large reef tank.

Care Information

• Maximum Size: Up to 8 inches.
• Tank Size: 180 gallons minimum; larger tanks are recommended due to its active swimming habits and territorial nature.
• Diet: Herbivorous; primarily feeds on algae and should be offered high-quality vegetable matter, seaweed, and spirulina-based foods. Occasional supplementation with meaty foods such as mysis shrimp can help diversify its diet.
• Water Temp: 75-82°F.
• Salinity: 1.020-1.025.
• Aggression: Semi-aggressive; can become territorial, especially towards other tangs and similar species. It is best to keep it with non-competing species in large tanks.
• Skill Level: Intermediate to advanced; requires stable water conditions, a large tank, and a varied diet to thrive.
• Reef Compatibility: Reef-safe; it does not harm corals or invertebrates and is beneficial for controlling algae growth in reef systems.

Aggression Warning
The Gem Tang can display territorial behavior, particularly towards other tangs or fish with similar body shapes. It is recommended to introduce the Gem Tang into a tank that has already been established with other fish, or as the last tang in the tank to minimize aggressive interactions.

Color Variation by Locality

• Western Indian Ocean (Mauritius): The Gem Tang from this region is famous for its jet-black body dotted with bright white or blue speckles, providing its "gem-like" appearance. The intensity and distribution of these spots may vary slightly based on the individual​.

Typical Habitat

• Distribution: The Gem Tang is found in the Western Indian Ocean, especially around the waters of Mauritius and the Seychelles. It typically inhabits coral reefs and rocky areas, where it grazes on algae​.