Whitetail Damselfish

Geographical Origin and Habitat: Western Indo-Pacific, distributed from the Maldives and Sri Lanka to the Solomon Islands, north to southern Japan, and south to northern Australia. Inhabits shallow coastal reefs and silty sandy lagoons.

Taxonomy and Morphology: Classified within the family Pomacentridae, subfamily Pomacentrinae. The specific name 'chrysurus' translates to golden tail, though the caudal fin is stark white in most regional populations.

Social Behavior: Territorial species that lives solitarily or in loose, small groups. Remains near shelter and defends a small feeding and breeding territory against intruders.

Coloration and Sexual Dimorphism: Adults feature a dark brownish-grey to velvety black body. The most distinctive feature is the stark white caudal fin. Juveniles may show thin blue lines on the head.

Aquarium Setup: Needs a tank of at least 100 liters with a layout of live rock providing various crevices and caves, set above a sandy substrate to simulate its natural habitat.

Diet and Feeding: Omnivorous. Feeds on algae and microinvertebrates in nature. Readily accepts flakes, pellets, frozen brine shrimp, mysis, and spirulina-based foods.

Water Quality: Standard marine parameters: temperature 23-28 °C, pH 8.1-8.4, and salinity 1.020-1.025 with standard filtration and moderate water movement.

Compatibility and Cohabitation: Semi-aggressive. Territorial towards other damselfishes and similarly sized fish. Best kept in a community aquarium with robust and active tankmates.

Aquarium Breeding: Oviparous. The male cleans a flat rock or cave ceiling, courts the female to spawn, and defends the adhesive egg clutch until hatching.

Risks and Diseases: Very hardy and highly resilient, making it suitable for beginner marine aquarists. Territorial behavior must be managed by avoiding cramped conditions.