Family: MONACANTHIDAE, Filefishes, Leatherjackets
Filefishes are small to medium sized fishes (up to ~ 50 cm, but most < 20 cm), and are close relatives of triggerfishes (Balistidae), that differ in having very compressed bodies; a long pointed snout; a small mouth that usually opens at the front; teeth moderately strong, six in outer row on top jaw and six or less in one row on bottom jaw; gill opening a short slit on side before pectoral base; 2 dorsal fins, 1st with II spines, the 1st spine long, usually can be locked in place by minute 2nd spine, which is lost in some species; median fins rays are unbranched; pelvic fins absent or reduced to a small, scaly spine; scales minute, innumerable, equipped with small hairs, cover skin and give it a coarse texture like sand-paper; no patch of enlarged scales above pectoral base; lateral line usually inconspicuous.
Most filefishes can change color to match their surroundings, small skin flaps or tassles in some species further enhancer camouflage. Filefishes tend to be secretive, often hiding in seagrass, thick algal cover, gorgonians, or coral. Most are omnivorous and feed on a great variety of benthic animal and plant life.
There are approximately 111 species from 26 genera worldwide; the majority are confined to cooler waters of temperate and subtropical seas. In our area there are three species, two circumtropical and one Indo-Pacific.