Acanthurus xanthopterus Valenciennes in Cuvier & Valenciennes, 1835
Yellowfin surgeonfish, Purple surgeonfish
Body an elongate oval; head profile steep; eye high on the head; mouth small, protrusible, low on head; teeth on jaws fixed, with flattened, notched tips, 8-28 on each jaw; gill rakers 16-24; dorsal rays IX, 25-27; anal rays III, 23-25; pectoral rays 16-17; pelvic fin I, 5; a large depressible spine fits into a groove on the side of the base of the tail; tail fin strongly concave; scales very small, rough; lateral line complete.
Purplish grey to brown, outer third of pectoral fin yellowish; yellow area around and in front of eye; base of tail fin often with white bar; can quickly assume a very pale grey coloration with numerous dark wavy lines on the side.
Size: 70 cm.
Habitat: generally seen in sandy areas.
Depth: 1-100 m.
Widespread in the tropical Indo-Pacific from East Africa to the Americas; in the eastern Pacific it ranges from the mouth of the Gulf of California to Ecuador and all the oceanic islands.