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Smooth Trunkfish

Lactophrys triqueter

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Field-guide illustration of Smooth Trunkfish (Lactophrys triqueter), showing its diagnostic body shape and markings.
Illustration for identification. Features may vary.

Fun facts for your next surface interval

  • It is smooth in the cowfish sense: no eye horns and no rear corner spines.
  • Youngsters can look like spotted little cubes with fins.
  • Its rigid body still leaves the tail and small fins free to do the steering.

Florida and local context

Florida marine waters; broader Florida scope: FWC includes smooth trunkfish among Florida marine-life finfish. Florida-wide scope; the Lake Worth Lagoon checklist does not explicitly verify it locally.

Documented regional presence is not a guarantee of an encounter or a measure of how common this animal is at your dive site.

How to recognize this animal

Smooth trunkfish wear pale spots over a dark brown or blackish armored body. A lighter honeycomb-like patch can appear on the middle of the side, while the lips and fin bases are dark. The decisive structural clue is what is absent: there are no horns above the eyes and no projecting spines at the lower rear corners of the carapace.

Size and life stages

The Smithsonian regional guide reports a maximum of about 12 inches, or 30 centimeters, in total length. That is the size reference used here rather than a measurement of local fish. Tiny juveniles have an especially rounded, boxlike appearance. Include the tail when estimating total length, and do not infer exact age from the apparent size of a photograph.

Habitat and where to look

Reef habitat supplies feeding surfaces and shelter, from relatively shallow water to deeper reef slopes. A trunkfish may be easy to overlook while it works close to rock or coral. Search with your eyes rather than a hand or camera pushed into a hole. Leave room for it to move into cover without having to squeeze past you.

Range and local context

This western Atlantic species occurs in Florida and continues through the Caribbean toward Brazil. Its inclusion here is Florida-wide. FWC recognizes it among Florida's marine-life finfish, while the Lake Worth Lagoon checklist does not explicitly verify it locally. Neither a wide distribution map nor a familiar aquarium species establishes that a particular Palm Beach site reliably holds smooth trunkfish.

What is on the menu?

The small protruding mouth picks up bottom-living food, including worms, crustaceans, mollusks and other invertebrates. The body may look like a floating box, but its mouth and fins carry out precise work. Watch what happens at the substrate without supplying food. A feeding observation is more useful when it records the fish's own choice rather than a staged interaction.

Daily habits and behavior

Much of the body is enclosed in a rigid carapace made from joined bony plates. Small fins and the flexible tail provide movement while the armored trunk stays comparatively stiff. No pelvic fins are present. Young fish can resemble dark, spotted little cubes, an appearance that becomes less rounded as their adult proportions develop.

Mating and the next generation

Early life includes pelagic eggs and larvae, so a bottom-associated adult begins with a water-column phase. The sources used for this entry do not establish a dependable Palm Beach spawning schedule. An isolated juvenile is not evidence of a nearby nest, and a brief meeting between adults is not enough to label a photograph as a spawning event.

Look-alikes and identification traps

Spotted trunkfish reverse the usual color relationship: dark dots lie on a pale body, and adults have rear lower corner spines. Honeycomb and scrawled cowfish have conspicuous eye horns. Check both the face and the rear of the armor before deciding. A dark image alone can hide pale spots and make pattern-based identification unnecessarily difficult.

Observe without disturbing

Keep a comfortable distance and never handle, corner or chase a trunkfish to make it turn. A side photograph showing the dark lips, pale spots and smooth rear corners records the strongest combination of clues. Avoid using a hand as a size reference beside it. A calm, complete view provides better evidence than a dramatic but obstructed close-up.

Harvest, protection and eating safety

Restricted marine life: live collection only; no spearing

Can it be hunted or harvested?

Smooth Trunkfish (Lactophrys triqueter) is restricted tropical ornamental marine life, not an ordinary food-fishing species or a blanket no-take species. Where collection is lawful, a saltwater fishing license is required unless exempt. Land and keep the fish alive with adequate circulation or aeration. No species-specific size limit is listed. Daily limit: five of this species within 20 marine-life organisms total per person. Two-day possession maximum: ten of this species within 40 organisms total. Recreational sale is prohibited.

Florida seasons and areas

No annual recreational closed months are listed for this marine-life species. Collection is prohibited within the designated Blue Heron Bridge dive-site boundary and throughout Biscayne National Park. Florida marine-life rules also apply in adjacent federal waters on both coasts. Check the exact sanctuary, park and refuge zone before collecting. Collection of this group is also prohibited in John Pennekamp Coral Reef State Park. Western Dry Rocks’ designated one-square-mile area is closed to all fishing April 1–July 31 annually.

Can it be speared?

No. Spears are not authorized recreational gear for this regulated tropical marine-life fish. Use only lawful live-collection methods, such as permitted hand-held, barrier or drop nets or a slurp gun, and comply with the live-landing requirement.

Is it safe to eat?

Do not treat this ornamental boxfish as a food fish based on this guide. No species-specific Florida consumption-safety clearance was verified. The live-collection rule is not an edibility finding, and cooking is not a general safeguard against marine toxins. Do not transfer pufferfish food-safety assumptions to cowfish or trunkfish.

Before you act: This recreational overview is not permission to collect or spear at your dive site. Confirm the species, date, management area, state or federal waters, gear, licenses and current local closures. Identification artwork cannot establish an identification or guarantee seafood safety.

Official rules and health guidance

Reviewed 2026-11-10. Rules and advisories can change; check the linked authorities before harvesting or eating.

Sources and review

Reviewed 2026-11-10.

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