Spotted trunkfish (Lactophrys bicaudalis)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Tetraodontiformes · Family: Ostraciidae · Genus: Lactophrys.

Accepted name: Lactophrys bicaudalis · Authority: (Linnaeus, 1758) · Taxonomic status: accepted · AphiaID: 275874.

Synonyms and superseded combinations recorded for this taxon: Lactyphrys bicaudalis (Linnaeus, 1758); Ostracion bicaudale Linnaeus, 1758; Ostracion bicaudalis Linnaeus, 1758; Ostracium bicaudale Linnaeus, 1758; Rhinesomus bicaudalis (Linnaeus, 1758).

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=275874 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Lactophrys bicaudalis. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 48 cm · Common length: 20 cm · Depth range: 3–50 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 38 of 100 · Fishery importance: commercial · Aquarium trade: commercial.

FishBase notes: Found in clear water around coral reefs. Sometimes under ledges and near small holes (Ref. 9710). Feeds on a variety of small bottom invertebrates such as mollusks, crustaceans, starfishes, sea urchins, sea cucumbers, sessile tunicates, sea grasses (Ref. 3696), algae, crabs and brittle stars (Ref. 13442). Toxins released when excited kills other fishes (Ref. 5521). Probably marketed fresh locally (Ref. 3696).

Source: FishBase species summary (SpecCode 4286) — https://www.fishbase.se/summary/Lactophrys-bicaudalis.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

21,969 georeferenced occurrence records for Lactophrys bicaudalis are published through GBIF from 38 countries or marine areas. The map above plots 101 distinct locations from a sample of 3,000 records, omitting 15 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: United States of America (18,486); Puerto Rico (2,369); Bonaire, Sint Eustatius and Saba (188); Mexico (170); Virgin Islands (U.S.) (129).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2408100) — https://www.gbif.org/occurrence/search?taxon_key=2408100&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=275874 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Lactophrys bicaudalis (Linnaeus, 1758) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 190106) — https://www.iucnredlist.org/species/190106/0; GBIF IUCN Red List category endpoint (taxonKey 2408100) — https://api.gbif.org/v1/species/2408100/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

The spotted trunkfish was first formally described as Ostracion bicaudalis in 1758 by Carl Linnaeus in the 10th edition of Systema Naturae with its type locality given as "India". The 5th edition of Fishes of the World classifies the genus Lactophrys within the family Ostraciidae in the suborder Ostracioidea within the order Tetraodontiformes.

The spotted trunkfish is a member of the genus Lactophrys, a name which is a compound of lactaria, meaning a "milkcow", and ophrys, meaning "eyebrow", a reference to the spines above the eyes resembling the horns of a cow. Some fishes in this family are known as cowfishes. The specific name, bicaudalis, means "two tailed", a reference to the two spines "below the tail", a mystery because this fish does not have any spines under its tail but there are two spines on either side of the anal fin.

Members of this family are known as boxfishes because they have a hard outer covering consisting of hexagonal plate-like scales fused together into a solid, triangular or box-like carapace. thumb|Honeycomb Cowfish fish caught in St. Kitts and NevisThe eyes, snout, fins and tail protrude from this. The spotted trunkfish is basically white or yellowish with a regular pattern of numerous black spots on the body and tailfin. Just behind the eye, adult fish have a diagonal row of three white spots where black ones would have been expected. The snout is plain white, with no spines above the eye and a pair of sharp spines in front of the anal fin.

The spotted trunkfish is found in the Caribbean Sea, the southern half of the Gulf of Mexico, Ascension Island and the northeastern coast of South America as far east as Brazil. It prefers clear water and is usually associated with coral reefs with fissures, holes and overhangs, at depths down to about 30 m.

Because of the heavy armoured scales, the spotted trunkfish is normally limited to slow movements, performed by rippling its dorsal and anal fins and gently beating its pectoral fins. If faster motion is required, it can additionally use the tail fin for propulsion. It is a benthic species, feeding on or near the seabed. Its diet includes crabs, shrimps, molluscs, sea urchins, starfish, brittle stars, sea cucumbers, tunicates and seagrasses.

The spotted trunkfish, like all trunkfish of the genus Lactophrys, secretes a colourless toxin from glands on its skin when touched. The toxin is only dangerous when ingested, so there is no immediate harm to divers. Predators as large as nurse sharks can die from eating a trunkfish.

Source: Wikipedia: Spotted trunkfish — https://en.wikipedia.org/wiki/Spotted_trunkfish (CC BY-SA 4.0). Accessed 2026-09-23.