Bicolor Angelfish

Geographic Origin and Biotope: Native to the tropical Indo-Pacific, from East Africa to the Samoan islands and southern Japan. Prefers steep reef slopes, coral drop-offs, and rocky lagoons at depths ranging from 1 to 25 meters, always in the vicinity of abundant hiding places.

Taxonomy and Morphology: Known as the Bicolor Angelfish. It is one of the largest species within the dwarf angelfish genus (Centropyge), reaching a substantial size of 15 cm (6 inches). Possesses the iconic lethal spine on the cheek (preopercle). Laterally compressed and deep body, to navigate through coral branches.

Social Behavior: Fish with a strong and territorial character. In the wild, harems consist of a dominant male patrolling a vast area populated by several females. In the aquarium, it is initially shy, then becomes the proud master of its rocks, chasing away anyone who dares to invade its main refuge.

Coloration and Sexual Dimorphism: Perfectly explanatory name: the front half of the body, pelvic fins, and tail are a bright luminous lemon yellow, while the entire rear half and a band over the eye (like a mask) are a very deep cobalt blue. Protogynous hermaphrodites (born female, the dominant one changes sex to become male).

Aquarium Setup: Tank of at least 250 liters (65 gallons), obligatorily rich in mature Live Rock offering crevices it can dive into at the slightest perception of danger. Needs ample free space for swimming. Intense lighting does not disturb it, provided there are shadows cast by the rocks.

Diet and Feeding: In the wild, it grazes almost exclusively on sponges, tunicates, filamentous algae, and diatoms. In the aquarium, this propensity makes it the worst enemy of corals: it is notorious for relentlessly destroying brain corals (LPS) and Zoanthids. Must receive a rich diet based on angelfish preparations (containing sponge extracts), Nori, spirulina, and mysis.

Water Quality: A decidedly demanding and delicate fish during acclimation. Temperature 24-28 °C (75-82 °F). Stable pH strictly above 8.1. Highly sensitive to nitrate accumulation and salinity fluctuations. It is one of the marine fish that benefits most from the use of UV-C sterilizers to reduce the bacterial load in the tank.

Compatibility and Tankmates: NOT RECOMMENDED for reef aquariums (Reef Safe: NO). It is preferable to keep it in FO (Fish Only) or FOWLR (Fish Only With Live Rock) aquariums. Extremely aggressive toward other dwarf angelfish. Coexists well with Butterflyfish, Tangs, large Damselfish, and peaceful Triggerfish.

Aquarium Reproduction: Not documented in amateur tanks. Reproduces at dusk by rising vertically in the water column and releasing fertilized pelagic eggs, which are dispersed in the open sea by currents. The young go through a planktonic stage that is impossible to sustain in captivity due to a lack of suitable micro-foods.

Risks and Diseases: Famous for having a dramatically low survival rate during the first month of introduction (the "Bicolor curse"). Extremely susceptible to marine velvet disease (Oodinium / Amyloodinium) induced by transport stress. Ensure you buy specimens that are already eating voraciously in the shop.