Filefish have a protruding mouth with some very sharp teeth, similar to a triggerfish. They have narrow, compressed bodies with rough spiny scales and a front dorsal fin that can be raised or lowered. When the fin is raised, it resembles a file, which some reference sources say is the inspiration for the name. Others attribute the moniker to the sandpaper-like quality of the scales. Whatever the true origin, filefish are another group of highly entertaining critters on the reef.
They eat a variety of things, but mostly algae, seagrass, soft corals and anemones. Scrawled filefish seem to have an affinity for munching on branching fire coral. I have also seen scrawled filefish pecking at a moon jellyfish in mid water.
Whitespotted filefish are usually very shy, and I have found it takes a bit of patience to get them oriented for a good photo. Their color changes from orange to a dull yellow and gray when they display the white spots.
Next on the elusiveness scale are the orangespotted filefish. They are quite a bit smaller than the scrawled or whitespotted varieties and tend to hide among the gorgonians and peak out at you before they bolt to a more secure spot.
To me the most difficult species to spot are the slender filefish. Not only are they quite small, typically about three inches or less in length, but they are quite adept at changing color to match the gorgonian they are hiding behind. We have seen them frequently on on top of the mini-wall on Deep Molasses.