Scientific name: 
Acanthurus chirurgus
Distinctive features: 
1. Always have body bars (10-12), although they may be quite faint.
Size: 
6-12 in. max. 14 in
Can change from bluish gray to dark brown, and pale or darken dramatically. Several markings radiate from eye. Blue or white edging on dorsal, anal and tail fins. May have pale band on base of tail.