The Dascyllus aruanus is from the order of Perciformes and family of Pomacentridae (Damselfishes). Their overall body colour is white with 3 black stripes. There is a large white spot on the dorsal part of the snout, between the eyes. Their lips are dusky or white. Its caudal fin is pale, while its pelvic fins are black and pectoral fins are transparent. It has a total of 12 dorsal spines, 11 to 13 dorsal soft rays, 2 anal spines and 11 to 13 anal soft rays. Sexual dimorphism is not prominent, both male and female display bright colours.
 Fishelson, ‘Behaviour, Socio‐ecology and Sexuality in Damselfishes (Pomacentridae)’; Phillips et al., ‘Disruptive Colouration in Reef Fish’; Chase et al., ‘Small-Scale Environmental Variation Influences Whether Coral-Dwelling Fish Promote or Impede Coral Growth’.
 ‘Dascyllus Aruanus Summary Page’.
This species is present across the Indo-Pacific region. It is found in shallow lagoons and subtidal reef flats. The recorded depth range reaches 20m. Large groups is present above the staghorn Acropora corals and smaller aggregations occur over isolated corals. Their diet consists of zooplankton and invertebrates found on or near the ocean floor as well as algae.
Adults usually form pairs during breeding. The male will choose the nest and perform a courtship dance 1 m above it, inviting females. Spawning occurs and eggs hatch within 3 to 5 days. Males become highly territorial and protective towards the eggs. The hatched larvae live in the water column, and feed on plankton.
The conservation status of this species has not been evaluated yet. It is part of aquarium trade which represents a potential threat.
This species can reach a maximum of 10cm.