Threeblotched rabbitfish (Siganus trispilos)

Classification (WoRMS)

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

Accepted name: Siganus trispilos · Authority: Woodland & Allen, 1977 · Taxonomic status: accepted · AphiaID: 273924.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273924 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (FishBase)

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

Maximum length: 25 cm · Depth range: 3–5 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 15 of 100.

FishBase notes: Strictly corallophilic, pairs living in area rich in hard coral, particularly Acropora .

Source: FishBase species summary (SpecCode 4612) — https://www.fishbase.se/summary/Siganus-trispilos.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

167 georeferenced occurrence records for Siganus trispilos are published through GBIF from 2 countries or marine areas. The map above plots 10 distinct locations from a sample of 167 records, omitting 2 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 (166); Thailand (1).

Source: GBIF Occurrence Search (taxonKey 2390371) — https://www.gbif.org/occurrence/search?taxon_key=2390371&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273924 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Conservation status (IUCN Red List)

The IUCN Red List assesses Siganus trispilos Woodland & Allen, 1977 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 241132598) — https://www.iucnredlist.org/species/241132598/0; GBIF IUCN Red List category endpoint (taxonKey 2390371) — https://api.gbif.org/v1/species/2390371/iucnRedListCategory. Accessed 2026-09-25.

Description and natural history (Wikipedia)

Siganus trispilos was first formally described in 1977 by the ichthyologists David J. Woodland and Gerald R. Allen with the type locality given as off Tantabiddi Creek at the North West Cape in Western Australia. The specific name trispilos is a compound of tri meaning "three" and spilos which means "mark" or "spot", a reference to the three large spots on the upper body.

Description

Siganus trispilos has a laterally compressed deep body, its depth fitting roughly twice into its standard length with a deeply forked caudal fin. The forward nostril opening is a tube which expands to the rear of the nostril into a wide flap. There is a procumbent 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. This species attains a maximum total length of 33.5 cm. The overall colour is vivid yellow with three large dark brown blotches on the upper flanks, tiny bluish ocelli dot the head, upper flanks and loweset surface of the body with an oblique, ill-defined brown stripe running through the eye.

Distribution and habitat

Siganus trispilos is endemic to the waters of the eastern Indian Ocean off northwestern Western Australia. It has been recorded from the waters from the Ningaloo Reef to the Corneliesse Shoal, which is northwest of Port Hedland. It is found in areas rich in hard corals, particularly being found in Acropora corals.

Biology

Siganus trispilos lives as pairs among the coral, where they browse on upright seaweeds. If disturbed the pairs will dart into the coral for shelter. This species produces venom in the spines of its fins. In a study of the venom of a congener it was found that rabbitfish venom was similar to the venom of stonefishes.

Source: Wikipedia: Siganus trispilos — https://en.wikipedia.org/wiki/Siganus_trispilos (CC BY-SA 4.0). Accessed 2026-09-25.