White-spotted spinefoot (Siganus canaliculatus)

Classification (WoRMS)

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

Accepted name: Siganus canaliculatus · Authority: (Park, 1797) · Taxonomic status: accepted · AphiaID: 219687.

Synonyms and superseded combinations recorded for this taxon: Amphacanthus dorsalis Valenciennes, 1835; Amphacanthus guttatus oramin Bloch & Schneider, 1801; Chaetodon canaliculatus Park, 1797; Siganus oramin (Bloch & Schneider, 1801); Teuthis dorsalis (Valenciennes, 1835); Teuthis oramin (Bloch & Schneider, 1801); Theutis dorsalis (Valenciennes, 1835).

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=219687 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

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

Maximum length: 40 cm · Common length: 20 cm · Depth range: 1–50 m · Habitat zone: reef-associated · Body shape: fusiform / normal · Vulnerability index: 31.4 of 100 · Fishery importance: commercial · Aquarium trade: never/rarely.

FishBase notes: Adults inhabit inshore, algae reefs, estuaries and in large lagoons with algae-rubble habitats. Mainly common on rocky substrates (Ref. 48637). In contrast to S. fuscescens , this species seems to tolerate more turbid waters, occurring within the vicinity of river mouths especially around seagrass beds. Adults also occur several kilometers offshore in deep, clear waters. Juveniles form very large schools in shallow bays and coral reef flats; school size reduces with size, with adults occurring in groups of 20 individuals or so. Herbivorous, feed on benthic algae and to some extent on seagrass. Fished by trawling and seine netting; bycatch in traps set in deep water and marketed fresh in very large numbers (Ref. 9813). Consumed as food; and have poisonous spines (Ref. 4537).

Source: FishBase species summary (SpecCode 4456) — https://www.fishbase.se/summary/Siganus-canaliculatus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

2,048 georeferenced occurrence records for Siganus canaliculatus are published through GBIF from 36 countries or marine areas. The map above plots 313 distinct locations from a sample of 2,048 records, omitting 64 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 (1,479); Kenya (154); Philippines (73); Thailand (48); Chinese Taipei (34).

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

Source: GBIF Occurrence Search (taxonKey 2390233) — https://www.gbif.org/occurrence/search?taxon_key=2390233&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=219687 (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 canaliculatus (Park, 1797) 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 46088346) — https://www.iucnredlist.org/species/46088346/0; GBIF IUCN Red List category endpoint (taxonKey 2390233) — https://api.gbif.org/v1/species/2390233/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Siganus canaliculatus was first formally described in 1797 as Chaetodon canaliculatus by the Scottish explorer Mungo Park with the type locality given as Bengkulu Province on Sumatra. This taxon is largely sympatric with the mottled spinefoot (Siganus fuscescens) and these taxa are also very similar in appearance. Molecular analyses in 2011 found that there were three separate lineages within S. canaliculatus and S. fuscescens, that these lineages interbred and that each lineage had specimens which referred to either taxon, this suggests that S. canaliculatus is a junior synonym of S. fuscescens. This is not the position taken by FishBase or Catalog of Fishes. The specific name canaliculatus means "grooved", a reference to the grooves in the fin spines. Park did not know that, like all rabbitfishes, these spines contained venom glands for defence.

Siganus canaliculatus has a moderately slender, laterally compressed body, the standard length being 2.3 to 2.8 times its depth. The dorsal profile of the head is weakly to notably concave over the eyes with a pointed snout. The front nostril has a flap, in juveniles this covers the rear nostril, although it becomes shorter as the fish grows and is completely absent in the oldest fishes. The dorsal fin has 13 spines and 10 soft rays while the anal fin has 7 spines and 9 soft rays. The front spine on the dorsal fin points forwards. The caudal fin is nearly emarginate in smaller individuals of less than 10 cm standard length becoming forked in larger fish. This species attains a maximum total length of 40 cm, although 20 cm is more typical.

The colour and pattern of the white-spotted spinefoot is very variable. It can be greenish grey to yellow brown and is marked with 100-200 perlescent blue to whitish spots on the nape and anterior part of the body, these are similar in size to a match-head on the lower flanks. There are 2 to 3 rows between the first spine of the dorsal fin and the lateral line, which are roughly one sixth the size of the eye, and another 10 or so rows between the uppermost point of the lateral line and the base of the first spine in the anal fin. Alarmed or injured fishes adopt a pattern where their flanks are mottled with patches of light and dark brown and cream, forming a pattern of 6 or 7 uniformly spaced, dark oblique zones with lighter zones of similar breadth separating them. There is normally dark spot immediately to the rear of the upper end of gill opening, this spot is similar in size to the eye, and a thin bar along the upper margin of the operculum.

Siganus canaliculatus has a wide Indo-Pacific distribution, ranging from the Persian Gulf to the Philippines and New Guinea, north to the Ryukyu Islands and south to northern Australia. It is found at depths down to 50 m with adults living in inshore waters, on algae reefs, in estuaries and in large lagoons where there is algae growing over rubble. The juveniles live in coral reef flats and shallow bays.

Siganus canaliculatus is said to be able to tolerate more turbid waters than the closely related S. fuscescens and may be found near river mouths, particularly where there are beds of sea grass. The adults can sometimes be found quite far offshore, in clear, deep waters. The juveniles form very large schools, which reduce in size as the fishes mature; adults occur in groups of around 20 individuals. When spawning, the adults gather in much larger aggregations. These fishes have only been observed to spawn from April to July. However, gonadosomatic indices suggest that there is another, less defined spawning period in November. Spawning events are synchronised with the lunar cycle. A mature female can spawn a number of times in a season, laying up to a million eggs. This is a herbivorous species which feeds on benthic algae and, to a lesser extent, on sea grass. This species, like other siganids, has venom glands located in grooves on the spines of the dorsal and anal fins.

White-spotted spinefoot was found to be a host of an intestinal acanthocephalan worm, Diplosentis amphacanthi.

Siganus canaliculatus is an important quarry species for commercial fisheries. In the Persian Gulf it is considered to be a good quality food fish, even though it is a rather small species. It is caught using bottom trawls and seine nets in coastal waters wherever it occurs. In the Persian Gulf, this species is caught largely by trapping in fences made up of nets in the inter-tidal zone and dome-shaped metal traps called gargoors. The fish landed are sold fresh in large numbers. This species is also taken as bycatch.

The Teochews of Singapore and Malaysia are particularly fond of this fish, which they refer to as pek tor her (). It is typically steamed and eaten with rice or as part of the Teochew porridge spread. The white-spotted spinefoot is particularly popular during Chinese New Year, when the fish is heavy with milt and roe and its consumption is considered auspicious. For this reason, it is also known as pai ni her ().

The white-spotted spinefoot has been used for mariculture in some areas in which it occurs because it has herbivorous habits, grows rapidly and is economically valuable. In some parts of this species' range the stock has been overfished.

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