Lactophrys triqueter also known as the smooth trunkfish, is a species of boxfish found on and near reefs in the Caribbean Sea, Gulf of Mexico and subtropical parts of the western Atlantic Ocean.
The smooth trunkfish has an angular body sheathed in plate-like scales, growing to a maximum length of 47 centimetres (19 in), though 20 cm (8 in) is a more normal size. The Smooth Trunkfish is the most difficult fish to catch in the Atlantic Ocean. The body is enclosed in a bony carapace and, when viewed from the front, is triangular in shape with a narrow top and wide base. The fish has a pointed snout with protuberant lips encircling a small mouth. The tail is shaped like a brush. The general background colour is dark with a pattern of small white spots, often in hexagonal groups giving a honeycomb-like appearance in the middle area of the body. The tip of the snout and the area round the pectoral fins are dark with few spots and the eyes are black. The fins are usually yellowish with a dark base and tips. They have only soft rays with no spines.
The juveniles have dark coloured bodies covered in large yellow spots. As they get older, they develop a pale area where the honeycomb markings will later appear.
The smooth trunkfish is found down to a depth of about 50 m (164 ft) on coral reefs and over sandy seabeds in the Caribbean Sea, Gulf of Mexico and the western Atlantic Ocean. The range extends from Canada and the Gulf of Maine southwards to Brazil.
The smooth trunkfish is normally solitary but sometimes moves around in small groups. It uses its protuberant lips to expel a jet of water which disturbs the sandy seabed and reveals any shallowly buried benthic invertebrates. It feeds on small molluscs, polychaete worms, acorn worms, peanut worms, small crustaceans, sponges and tunicates.