Gem Tang (Zebrasoma gemmatum) known to tropical fish keeping enthusiasts as the Spotted Tang or Mauritian Tang is found in the Western Indian Ocean and ranges from the coast of Mozambique, South Africa and Madagascar to the Islands of Mauritius and Réunion.
The Gem Tang is a rare, solitary, and highly prized species that inhabits the coral and rocky reefs of the range at depths from 35 to over 200 feet where they can be found grazing on algae. Juveniles prefer relatively shallower depths, whereas adults are normally found in deeper waters and surge zones.
The Gem Tang has a stunning black body covered with a galaxy of vibrant white spots, a bright yellow caudal fin, and yellow accents on the pectoral fins. There are no external characteristics that can determine males from females.
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The Spotted Tang is best housed in a mature FOWLR or reef aquarium of at least 180 gallon capacity with a crushed coral or sandy substrate, plenty of live rock arranged into caves, crevices, and overhangs, and plenty of free swimming area. Gem Tangs are completely reef safe and do well in large reef tanks. Although they are very territorial and will fight with other tangs, particularly other Zebrasoma tangs; Zebrasoma gemmatum will normally ignore other similar sized fish species.
If its not possible to keep your Gem Tang isolated from other tang species in a large tank, make sure to introduce all the tangs at the same time to minimize aggression. On the reef, Gem Tangs are very territorial and are mostly encountered as lone specimens.
Zebrasoma gemmatum are open water egg scatterers that have not yet been bred in an aquarium environment.
In their natural habitat on the rocky reefs, Gem Tangs spend their time grazing primarily on algae. In an aquarium environment, they will pick at algae on mature live rock but still require a steady diet of brown, purple, and green marine algae; along with some meaty foods.
Dried Nori seaweed tied to a rock or on a veggie clip, Sea Veggies, Seaweed Salad, and Ocean Nutrition Seaweed Select are all ideal, easy to use products. Occasional meaty fare like brine shrimp, mysis shrimp, and finely chopped pieces of fresh shrimp, scallops, mussels, clam, etc. should be offered to round out their diet.
A varied, but herbivore weighted diet is important to strengthen the fishes immune system, reduce aggression, and improve their overall health.
Because of the rarity and the fact that the Gem Tang (Zebrasoma gemmatum) comes from deeper waters and surge zones of their range which makes collecting them extremely difficult, they command a high price.
Tropical fish keeping enthusiast can find them online from a variety of wholesalers and retailers at purchase sizes of 3″ to 4″ at prices that vary from $499.00 to over $1762.99; to over $2000.00 for 5.25″ to 6.25″ specimens.
Minimum Tank Size: 180 gallons
Aquarium Type: Reef or FOLR
Care Level: Moderate
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Max. Size: 8.7″
Color Form: Black, White, Yellow
Diet: Herbivore
Compatibility: Reef
Origin: California, Mexico
Family: Acanthuridae
Lifespan: 7 to 10 years, possibly longer
Aquarist Experience Level: Intermediate