Fiji Blue Devil Damselfish, also known as the South Seas Devil Damselfish or Village Belle, is blue with a yellow belly. It is considered aggressive and should not be mixed with its own species or passive fish. It does better with larger fish in aquariums 30 gallons or larger.
The South Seas Devil Damselfish feeds on a variety of meaty items, herbivore preparations, and flaked foods.
Source: Live Aquaria