Acanthurus lineatus Their colorful striped markings give them the name "clown" or "lined tang" or "blue-lined tang". They are indeed beautiful. However, they are not an easy fish to keep. Difficult to acclimate, and more delicate than most other surgeonfish, they should only be attempted by a more advanced aquarist. Also, they get quite large (10-12") and aggressive as they age. Ideally, they should be kept in a 180 gallon or larger aquarium, if you want to be able to keep them for their entire life.