Zebrasoma gemmatum, the gem tang, spotted tang or Mauritian tang, is a marine reef tang in the fish family Zebrasoma. They may live at water depths of 10–61 m or more. The fish grow to a maximum length of 22 cm. Zebrasoma gemmatum is found in the Western Indian Ocean off the coast of Mozambique, South Africa and Madagascar and near the islands of Réunion and Mauritius. Z. gemmatum is a highly prized specimen by marine aquarists and often commands prices of $3000 or more.