Fish ID: Sergeant Major

Damselfish sergeant major nsw
Family Damselfish (POMACENTRIDAE)
species Abudefduf vaigiensis
size To 18cm
locality Shoreline reefs and rocks
behaviour Usually in groups
range Africa to Red Sea, to south Japan, Eastern Pacific

Also called the Indo-Pacific or Banded Sergeant for self-explanatory reasons.  Has five vertical bars (including one at base of tail) usually blue but sometimes almost black and often yellow on top.