Xanthichthys
From Microcosm Aquarium Explorer
Family: Balistidae
Species in Genus Xanthichthys:
XANTHICHTHYS TRIGGERFISHES
These are easily the best triggerfishes for the reef aquarium. On rare occasions, these species may nip at sessile invertebrates or attack delicate crustaceans, like anemone shrimp (Periclimenes species), but most individuals will behave themselves when it comes to corals.
They are rarely aggressive toward their tankmates, unless the latter are much smaller and/or introduced to the aquarium after them. Larger individuals have been known to prey on small fishes. In larger tanks, they tend to ignore smaller fishes.
If your tank is large enough (100 gal. [380 L] or more), you can even keep them in male-female pairs (most members of the genus exhibit color differences between the sexes).