Acanthurus tennentii

Acanthurus tennentii, commonly known as Lieutenant surgeonfish or The Vampire Tang.
Widespread Indian Ocean, ranging to Bali where it mixes with Acanthurus olivaceus. Occurs in
small groups on reef flats and slopes. Identified by the bluish black colour, peduncular spine
surrounded by black with blue edge, and a black mark above pectoral fin base that develops into
short, double stripes. Juveniles black to yellow body, yellow caudal fin and dark eye. Grows upto 31cm.