Acanthurus triostegus (convict surgeonfish, convict tang)

Three different species all hanging out together - how nice. It's seems to me that the larger black fish defeats the camouflage of the smaller lined fish (silhouetting them), but I guess that's a little difficult for the fish to figure out. The fish with the vertical bars are called Convict Tang's (Acanthurus triostegus). The larger black fish are probably Ring Tail Surgeonfish (Acanthurus blochii) but the photo is quite low quality.