Yellow boxfish (Ostracion cubicum)

Classification (WoRMS)

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

Accepted name: Ostracion cubicum · Authority: Linnaeus, 1758 · Taxonomic status: accepted · AphiaID: 403462.

Synonyms and superseded combinations recorded for this taxon: Ostacion cubicus Linnaeus, 1758; Ostracion argus Rüppell, 1828; Ostracion cubicua Linnaeus, 1758; Ostracion cubicus Linnaeus, 1758; Ostracion tuberculatus Linnaeus, 1758.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=403462 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

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

Maximum length: 45 cm · Depth range: 1–280 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 35 of 100 · Fishery importance: minor commercial · Aquarium trade: commercial.

FishBase notes: Inhabit lagoon and semi-sheltered seaward reefs. Juveniles often among Acropora corals (Ref. 9710). Benthopelagic (Ref. 58302). Solitary (Ref. 5503). Juveniles expatriating to subtropical zone from the pelagic larval stage. Small juveniles secretive in narrow crevices (Ref. 48637). Feed primarily on algae with a compliment of microorganisms, invertebrates, mollusks, sponges (Ref. 5503), sand dwelling polychaetes, crustaceans, foraminiferans, and fishes (Ref. 37816).

Source: FishBase species summary (SpecCode 6555) — https://www.fishbase.se/summary/Ostracion-cubicum.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

5,669 georeferenced occurrence records for Ostracion cubicum are published through GBIF from 71 countries or marine areas. The map above plots 362 distinct locations from a sample of 3,000 records, omitting 47 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: Australia (1,659); Indonesia (643); Egypt (426); New Caledonia (355); French Polynesia (328).

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

Source: GBIF Occurrence Search (taxonKey 5213766) — https://www.gbif.org/occurrence/search?taxon_key=5213766&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=403462 (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 Ostracion cubicum 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 193777) — https://www.iucnredlist.org/species/193777/0; GBIF IUCN Red List category endpoint (taxonKey 5213766) — https://api.gbif.org/v1/species/5213766/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

The yellow boxfish was first formally described by Carl Linnaeus in the 10th edition of Systema Naturae published in 1758 with its type locality given as India.

The classification of O. cubicum was at first debated. Carl Linnaeus used both the names O. cubicum and O. tuberculatum in order to describe the yellow boxfish. Because of the scarcity of comprehensive descriptions of the fish in Linnaeus' work, it was unclear if these two names were to classify different species. Albert Gunther was the first to resolve this debate, concluding that they were one species as it was difficult to distinguish the two. He placed O. cubicum as the valid species name and O. tuberculatum in synonymy.

This species is the type species of the genus Ostracion, which the 5th edition of Fishes of the World classifies within the family Ostraciidae in the suborder Ostracioidea within the order Tetraodontiformes. The family Ostraciidae includes fish known for their boxy shape, like cowfishes and trunkfishes.

The yellow boxfish is the type species of the genus Ostracion, this name means "little box" and is an allusion to the shape of the body of the species. The specific name, cubicum means "cubic" and is a reference to the box-like shape of this fish.

The yellow boxfish reaches a maximum length of 45 cm. As the name suggests, it is box-shaped. Boxfish are also known for their armored and rigid body called a carapace, covering the head and body. There are openings in the carapace for the mouth, nostrils, gill opening, anus, caudal peduncle, and fins. The rigid body shape provided by the carapace surrounding the body was thought to help the fish stabilize while swimming as the water flows over the body. It was thought to keep them on course in high-flow, turbulent conditions. However, the carapace was found to have little effect on stability. In fact, it was destabilizing, as it increased drag. Instead, the caudal fin is the stabilizing force and acts as a rudder.

Despite having a stiff and rigid covering, the yellow boxfish are strong and swift swimmers. They are able to swim steadily for long periods and they are able to maneuver in complex reefs. It was thought that boxfish swam with burst movements and by sculling their fins like an oar of a boat. However, they use a combination of movements with their dorsal, anal, and pectoral fins. The dorsal and anal fins move stiffly either simultaneously or non-simultaneously. It is with these fins they can reach maximum speeds. The pectoral fins provide thrust, moving in a figure-eight motion. At low speeds, the fish rely primarily on their pectoral and anal fins. At more moderate and faster speeds, this transitions to dorsal and caudal fin dominant.

Additionally, boxfish have a keel that aid them in swimming. A keel is a ridge near the caudal peduncle, aiding in support and stability. For the boxfish, its keel helps with stabilization against roll.

When juvenile, it is bright yellow in color. As it ages, the brightness fades and very old specimens have blue-grey to black coloration with faded yellow.

Yellow boxfish are solitary animals. Breeding occurs during the spring, in small groups that consist of 1 male and 2–4 females.

The yellow boxfish could be confused with the spotted boxfish (Ostracion meleagris). They both have the same box-like shape and spots all around their body. However, the major differences between the two is their coloring. The yellow boxfish is mainly a bright yellow color with dark spots while the spotted boxfish is darker with white spots.

The yellow boxfish has a wide Indo-Pacific distribution which extends from the Red Sea and the eastern coast of Africa as far south as South Africa east to Hawaii, north to Japan and south to northern New Zealand. It has been recorded in the eastern Mediterranean Sea, probably having travelled through the Suez Canal. This species is found at depths between 1 and 75 m on sheltered coastal and offshore coral reefs and in areas of flat seabed.

They are adapted to be able to maneuver through the channels and crevices of coral reefs, as well as consume the benthic invertebrates that also live in the reefs.

The yellow boxfish's diet consists mainly of benthic organisms and marine algae. Their diets may also include worms, sponges, crustaceans, molluscs, and small fish.

Source: Wikipedia: Yellow boxfish — https://en.wikipedia.org/wiki/Yellow_boxfish (CC BY-SA 4.0). Accessed 2026-09-23.