Gem Tang

Zebrasoma gemmatum

Midnight blue scattered with white pearls and a bright yellow tail. One of the most expensive fish in the reef hobby.

A semi-aggressive saltwater fish that grows to 22 cm, lives in the middle of the tank and needs 24–27 °C, pH 8.0–8.4 and an aquarium of at least 500 L.

Care at a glance

Water

Saltwater

Temperature

24–27 °C (75–81 °F)

pH

8.0–8.4

Adult size

22 cm (8.7 in)

Aquarium

500 L or bigger (132 US gal)

Temperament

Semi-aggressive

Group size

Fine on its own

Swims

Middle

Diet

Herbivore

Wild home

Deep reefs off Mauritius & Madagascar

Good to know

• Algae eater. Keeps algae under control.
• Territorial. Fights other territorial fish in its zone, especially in small tanks.

Tank mates

Good company: Blue-Leg Hermit Crab, Copperband Butterflyfish, Firefish Goby, Foxface Rabbitfish, Mandarin Dragonet, Moorish Idol, Neon Goby, Regal Angelfish, Skunk Cleaner Shrimp, Snowflake Moray.

Fights with: Achilles Tang, Powder Blue Tang, Yellowtail Damselfish.

Attacked by: Clown Triggerfish.

Eats the newborn fry of: Neon Goby.

Colours

• Classic legendary

The care values are the ones Aquarius uses, based on how these animals live. Tank mates follow the game's rules: water type, temperature and pH, who can swallow whom, fin nipping, temperament and territory.