Chaetodontidae

Mailed butterflyfish

Chaetodon reticulatus

Chainmail scales patrolling coral reefs in pairs

• Tropical
• Regional distribution
• Marine fish
• Pacific Ocean
• Deep-bodied
• Compressed cross-section
• Medium
• Tropical fish

The mailed butterflyfish (Chaetodon reticulatus) is a marine reef fish native to the central and western Pacific Ocean. It is distinguished by its chainmail-like appearance: flank scales feature pale centers framed by bold black margins, complemented by a prominent ocular bar, a broad white band behind the head, and deep black dorsal and anal fins edged in radiant blue. Inhabiting clear, coral-rich seaward reef slopes down to thirty meters, adults form devoted monogamous pairs that patrol their territory together. As obligate corallivores, they feed almost exclusively on the polyps and mucus of live branching corals, making them an important indicator species for healthy coral reef ecosystems.