The South Seas Devil Damselfish, also called the Fiji Blue, is native to reefs of the Australasian western Pacific.
The fish is bright blue and the darker male has a yellow underside, tail and dorsal fin, but the blue depth of colour varies to dark blue/purple.
There is a black spot at the base of the dorsal fin and a black line through the eyes. Females have white bellies.
The fish grow to 8cm long and are aggressive to other small fish.