Genicanthus lamarck, commonly called Blackstriped Angelfish or Lamarck's Angelfish among various vernacular names, is a species of marine fish in the family Pomacanthidae. The Blackstriped Angelfish is widespread throughout the tropical waters of the Indo-West Pacific. It feeds on plankton along coral reefs. Sexual dimorphism occurs in the species of angelfish, the male is larger with blackish pelvic fins and a yellow spot on the front head, whereas the smaller female has brighter (white) pelvic fins.