Barhead spinefoot (Siganus virgatus)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Acanthuriformes · Family: Siganidae · Genus: Siganus.

Accepted name: Siganus virgatus · Authority: (Valenciennes, 1835) · Taxonomic status: accepted · AphiaID: 273928.

Synonyms and superseded combinations recorded for this taxon: Amphacanthus notostictus Richardson, 1843; Amphacanthus virgatus Valenciennes, 1835; Siganus notostictus (Richardson, 1843); Siganus virgata (Valenciennes, 1835); Teuthis notosticta (Richardson, 1843); Teuthis virgata (Valenciennes, 1835); Theutis virgata (Valenciennes, 1835).

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273928 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

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

Maximum length: 30 cm · Common length: 20 cm · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 20 of 100 · Fishery importance: minor commercial · Aquarium trade: commercial.

FishBase notes: Inhabits shallow coastal waters, around hard coral reefs and areas of sand with patches of rock and soft coral. Tolerant of murky waters. Larger juveniles and adults occur in pairs in coastal reef flats, slopes and estuaries . Small juveniles are found in mangroves and enter freshwater, moving to reefs usually in small groups among corals (Ref. 48637). Feed on benthic seaweeds (Ref. 9813).

Source: FishBase species summary (SpecCode 4624) — https://www.fishbase.se/summary/Siganus-virgatus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

1,476 georeferenced occurrence records for Siganus virgatus are published through GBIF from 18 countries or marine areas. The map above plots 205 distinct locations from a sample of 1,476 records, omitting 50 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 (562); Thailand (232); Philippines (203); Indonesia (186); Malaysia (138).

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

Source: GBIF Occurrence Search (taxonKey 2390240) — https://www.gbif.org/occurrence/search?taxon_key=2390240&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273928 (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 Siganus virgatus (Valenciennes, 1835) 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 117007442) — https://www.iucnredlist.org/species/117007442/0; GBIF IUCN Red List category endpoint (taxonKey 2390240) — https://api.gbif.org/v1/species/2390240/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Siganus virgatus was first formally described in 1835 as Amphacanthus virgatus by the French zoologist Achille Valenciennes with the type locality given as Java. The specific name virgatus was not explained by Valenciennes but it means "striped", this is presumed to be a reference to the two oblique brown bands on the front part of the body and head of this fish. Siganus virgatus is closely related to S. doliatus, with which it is apparently hybridized in the Indo-Malay region.

Siganus virgatus has a deep and laterally compressed body which has a depth which fits 1.8 to 2.3 times into its standard length.

high flange, slightly higher and pointed to the rear. There is a recumbent spine to the front of the dorsal fin. Like all rabbitfishes, the dorsal fin has 13 spines and 10 soft rays while the anal fin has 7 spines and 9 soft rays. The fin spines hold venom glands. The caudal fin is emarginate in juveniles and slightly forked in adults. This species attains a maximum total length of 30 cm, although 20 cm is more typical. The body of this species is pale with a silvery white belly. There are two wide diagonal dark bands on the head and the anterior part of body. The head and the front part of the body are marked with light bluish spots and lines. The caudal and dorsal fins are yellow and they normally have a yellow back and caudal peduncle.

Siganus virgatus is found in the Indo-Pacific region from southern India and Sri Lanka eastwards to West Papua and Western Australia, north to the Ryukyu Islands. An individual was collected off the Adriatic island of Cres, but it thought that this is the result of deliberate introduction or transportation in ships ballast. In Australia they are found from the Ningaloo Reef and Kimberley region in Western Australia along the northern coast to the Wessell Islands of the Northern Territory. They inhabit in tropical waters, associated with coastal coral reefs, in lagoons and outer reefs. They frequent rocky and hard coral areas with patches of sand. They are tolerant of turbid waters. Large juveniles and adults occur in pairs on slopes of reefs and estuaries. Small juveniles inhabit mangroves, moving to reefs in small groups, protected by coral reefs. They are found at depths down to 12 m.

Siganus virgatus is oviparous and the eggs are fertilized externally, laying sticky eggs. Spawning occurs at dusk, in the hot months, coinciding with the lunar cycle, in the first quarter of the moon. They possess a planktonic larval state, and develop a post-larval state, characteristic of the suborder Acanthuroidei, called acronurus, in which the individuals are transparent, and they remain in pelagic state during an extended period before establishing in the definitive habitat, and adopt then the shape and color of adults. They are mainly herbivores, in 84% of their nourishment. They progress from feeding on phytoplankton and zooplankton, like larvae, to feeding on benthic macroalgae and small invertebrates.

They are diurnal. At night they sleep in cracks, developing a specific coloration of camouflage, in brown tones, and turning off their lively colors, in an exercise of crypsis, that also develop when they are stressed.

Source: Wikipedia: Siganus virgatus — https://en.wikipedia.org/wiki/Siganus_virgatus (CC BY-SA 4.0). Accessed 2026-09-23.