Bicolor Angelfish

The Bicolor Angelfish is a small dwarf angelfish (genus Centropyge, family Pomacanthidae) prized for its striking two-tone coloration, bright yellow at the front and deep blue at the rear. Native to the Indo-Pacific, it inhabits coral and rocky reefs where it forages among rubble and coral crevices for algae and small invertebrates. Like other pygmy angelfish, it is a protogynous hermaphrodite, capable of changing sex from female to male within a small harem group. The species is common throughout much of its range and is a popular choice in the marine aquarium trade due to its manageable size and bold coloration, though its diet can make it challenging to maintain in captivity.

• Body: Small, oval, and strongly compressed, typical dwarf angelfish shape
• Color pattern: Sharp division between a bright yellow front half (head, chest, and forward body) and a dark blue to violet rear half
• Fins: Dorsal and anal fins edged in blue; pelvic fins yellow
• Size: Compact, rarely exceeding 15 cm
• Look-alikes: Similar in pattern concept to the Oriental Sweetlips juvenile, but the sharp color break and angelfish body shape are diagnostic The clean vertical color split with no gradient is the most reliable field mark for this species.

Bicolor Angelfish are distributed across the Indo-Pacific, from the eastern Indian Ocean through Southeast Asia to the western Pacific and northern Australia. They inhabit coral-rich reef flats, lagoons, and outer reef slopes at depths generally from 1 to 25 meters, in water temperatures around 24-28°C. They favor areas with a mix of coral, rubble, and algae growth, where they can forage while staying close to shelter. As with most dwarf angelfish, they are found in association with a specific home range rather than roaming widely across open reef.

Bicolor Angelfish are generally found alone, in pairs, or in small harem groups consisting of one male and several females, each maintaining a home territory on the reef. They forage during the day, picking filamentous algae, small invertebrates, and detritus from rock and coral surfaces, and retreat into crevices at night or when threatened. As protogynous hermaphrodites, all individuals start life as females, with the largest female in a group changing sex to male if the resident male is lost. Courtship and spawning typically occur at dusk, with pairs rising into the water column to release eggs and sperm, which then drift as part of the plankton before larvae settle back onto reef habitat.