Gem Tang - (Zebrasoma gemmatum) The Gem Tang will a reach an maximum size of 8”. As with most tangs, they are very active by nature so a generously-sized aquarium would be required to give it the swimming space needed. Specimens kept in smaller aquariums can become territorial and as they don't tend to accept other members of the same genus it is advisable to keep to just this one species of Zebrasoma in your aquarium. Other tangs from different genera with a visibly different appearance may be