Butterfish, a fish of the Atlantic Ocean that has a slippery coating of mucus. The butterfish is a food fish that reaches a length of six to nine inches (15 to 23 cm). It has a flattened, rounded body and a small forked tail. The color is silvery. Butterfish live in schools near sand-bottomed, shallow water. They are caught in fish traps.

The butterfish is Peprilus (or Poronotus) triacanthus of the butterfish family, Stromateidae.

The butterfishThe butterfish has a slippery coating of mucus and a flattened, rounded body.