Blackback butterflyfish

This fish grows up to 18 cm (c.7 in) long, and may live for up to 20 years. When observed at night or when frightened, this species changes color; the dorsal portion of the body turns black except for two white patches.

These oviparous fish are common on staghorn coral thickets, they are less seen on exposed parts of reefs. Black-backed butterflyfish are generally found between 4 and 20 m deep, usually solitary, in pairs during the breeding season.