Trunkfish, Lactophrys trigonus

The Trunkfish Lactophrys trigonus, whose common Spanish name is chapin búfalo, is a member of the Boxfish or Ostraciidae Family, known collectively as peces cofre in Mexico. This fish is also known as the Buffalo Trunkfish. There are only three global members in the genus Lactophrys, all three being found in Mexican waters of the Atlantic.

The Trunkfish have oblong thick bodies with a humped back and are enclosed in a bony box formed by thickened, joined, enlarged, and hexagonal scale plates. The box has openings for the mouth, eyes, gill slits, fins, and tail. Their body is triangular-shaped being narrow on top and wide at the base. They are light brown with a greenish tint and are covered with small diffuse white spots. They have two areas where the hexagonal plates have dark edges and form chain-like markings, one on the pectoral region and the other on the central body. These chain-like markings transition to an irregular dark reticulated pattern in mature individuals. Juveniles are orange to lime-green with scattered small white ringed dark spots that are darker around the pectoral fin and mid-body. They have a pointed snout with protuberant fleshy lips encircling a small mouth that opens in the front and is equipped with small conical teeth and short gill slits. Their anal and dorsal fins are far back on the body. Their caudal fin is fan-like and rounded. Their anal fin has two sharp spines. They do not have pelvic fins or spines on their fins. Their lateral line is inconspicuous.

The Trunkfish are slow swimmers found in and around seagrass beds, mangroves, coral rubble areas, and offshore reefs at depths up to 165 feet. They are the largest of the trunkfish reaching 55 cm (22 inches) in length and 3.3 kg (6.6 pounds) in weight. They feed on a wide variety of benthic invertebrates including crustaceans, mollusks, sea grasses, sessile tunicates, and worms. They are an uncommon and poorly studied species and very little is known about their behavioral patterns.

In Mexican waters the Trunkfish are found in all waters of the Atlantic.

The Trunkfish is similar in size and shape to several other trunkfish, however only the Smooth Trunkfish, Lactophrys triqueter, has spots, although these spots are small, white and very numerous.

The Trunkfish are considered an important food fish in many parts of the Caribbean.

Trunkfish Lactophrys trigonus. Fish caught from coastal waters off Islamorada, Florida, April 2012. Length: 20 cm (7.9 inches). Catch, photo and identification courtesy of George Brinkman, Guelph, Ontario, Canada.