Hawaiian Dascyllus

Geographic Origin and Biotope: Eastern Central Pacific, endemic to the Hawaiian Islands and Johnston Atoll. Inhabits shallow reefs, often associated with Pocillopora corals.

Taxonomy and Morphology: Family Pomacentridae. Deep, compressed, and rounded body with a blunt head and small mouth. Reaches about 12 cm in length.

Social Behavior: Highly territorial and aggressive, especially as an adult. Juveniles live in small protective groups among coral branches, but adult males defend territories aggressively.

Coloration and Sexual Dimorphism: Deep black body in juveniles with a single prominent white spot on the upper side. Colors fade to a dull dark gray as they mature. No sexual dimorphism.

Aquarium Setup: Requires a tank of at least 150 liters with a strong layout of live rock to define territories and provide retreats.

Diet and Feeding: Omnivore. Enthusiastically accepts all foods: frozen (mysis, krill), dry flakes or pellets, and herbivore preparations.

Water Quality: Very tolerant and hardy: temperature 23-27°C, pH 8.0-8.4, salinity 1.020-1.025. Standard efficient filtration is sufficient.

Compatibility and Tankmates: Avoid keeping with small or peaceful fish (e.g. gobies, pipefish). Keep only with robust and active fish such as surgeonfish, large wrasses, or triggerfish.

Aquarium Reproduction: Spawns adhesive eggs on flat rock surfaces. The male takes care of parental duties and will attack any intruder near the nest.

Risks and Diseases: Exceptionally hardy fish. The primary risk is its extreme aggressiveness, which can disrupt tank harmony.