The largest anemonefish, and the only one with a spine on the cheek.
Females reach about 17 cm and are deep maroon to almost black with three narrow bars that fade with age; males stay around 7 cm and are bright orange-red with clean white bars. The size difference between the sexes is the largest in the family, and a pair looks like an adult with a juvenile of another species. A backward-pointing spine on the cheek below the eye gives the species its name and its separate genus.
It uses only the bubble-tip anemone Entacmaea quadricolor, and a host normally holds one female and one male with no subordinates. Females are markedly aggressive and will strike a mask or a port repeatedly; the behaviour is worth expecting rather than reacting to. Recorded from about 2 to 20 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
