### Identification Commonly known as the Barred Filefish, this robust, laterally compressed species reaches about 15 inches in length. Its body is a subtle grayish-brown, but look closely for its defining field marks: roughly 12 dark, vertical bars flanking the rear half of the body and a brilliant, sun-yellow iris. Unlike the more flamboyant Scrawled Filefish, *C. dumerilii* sports a "velvety" texture and lacks neon-blue spots. Its most reliable diagnostic feature is the pair of forward-curving, bright orange spines on the caudal peduncle (the base of the tail), which look like tiny, sharp spurs.
### Habitat & Range This is a wide-ranging Indo-Pacific traveler, found everywhere from the coast of East Africa to the Revillagigedo Islands off Mexico. In the field, look for them along clear seaward reef slopes and deep lagoons, typically at depths between 10 and 115 feet. They are inextricably linked to healthy coral ecosystems.
### Behaviour Observing a Barred Filefish requires patience; they are shy, retiring spirits that usually travel in monogamous pairs. They are "crevice-huggers"—if they feel threatened, they won’t swim for the open blue. Instead, they’ll duck into a coral head and "lock" themselves in by wedging a stout dorsal spine into the reef ceiling. You’ll often see them hovering head-down, meticulously inspecting the reef for their next bite.
### Diet These fish are specialized corallivores. They use their powerful, beak-like teeth to nip the tiny polyps off *Pocillopora* (cauliflower) corals. While coral is their staple, they are opportunistic enough to crunch on sea urchins, sponges, and small tunicates when the mood strikes.
### Fascinating Fact Their skin is so exceptionally rough—composed of thousands of microscopic, hooked scales—that it was historically used by various Pacific Island cultures as a natural sandpaper for polishing fine woodwork and finishing dugout canoes!