File Fish, any individual of the genus Balistes, of the family Sclerodermi, with about thirty species, from tropical and subtropical seas. There are strong teeth in both jaws, by which these fish break off the coral, or crush the shells of the molluscs, on which they feed. The first of the three dorsal spines is rough in front, whence the popular name. They are also called Trigger-fish, from the fact that the second dorsal spine must be pushed down before the first can be depressed, the second spine being compared to a trigger. Two species, B. maculatns and B. capriscus, sometimes occur on the British coast. All are unfit for food.