Black foxface (Siganus niger)
Source-cited species reference: taxonomy from WoRMS, biology from FishBase, occurrence map from GBIF, conservation from IUCN Red List, description from Wikipedia.
The black foxface (Siganus niger) is a species of marine ray-finned fish, a rabbitfish belonging to the family Siganidae. It is endemic to Tonga in the western Pacific Ocean.
- Scientific name
- Siganus niger
- Authority
- Woodland, 1990
- Family
- Siganidae
- Order
- Acanthuriformes
- Maximum length
- 22 cm
- Depth range
- 2–15 m
- Habitat zone
- reef-associated
- Iucn red list
- Vulnerable
- Gbif occurrence records
- 35
Classification (WoRMS)
Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Acanthuriformes · Family: Siganidae · Genus: Siganus.
Accepted name: Siganus niger · Authority: Woodland, 1990 · Taxonomic status: accepted · AphiaID: 273918.
Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273918 (CC BY 4.0). Accessed 2026-09-23.
Biology and life history (FishBase)
Measured values published by FishBase for Siganus niger. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.
Maximum length: 22 cm · Depth range: 2–15 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 12 of 100 · Fishery importance: commercial · Aquarium trade: never/rarely.
FishBase notes: Prefers areas of staghorn or fire corals, or around rubble mounds composed of plate and staghorn corals. Subadults and adults in pairs, juveniles probably form schools. Feeds on seaweeds. Marketed fresh (Ref. 9813).
Source: FishBase species summary (SpecCode 4632) — https://www.fishbase.se/summary/Siganus-niger.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.
Distribution and occurrence records (GBIF)
35 georeferenced occurrence records for Siganus niger are published through GBIF from 2 countries or marine areas. The map above plots 6 distinct locations from a sample of 35 records; it shows where the species has been observed and reported, not a modelled range.
Most records by country or area: Tonga (34); Fiji (1).
Source: GBIF Occurrence Search (taxonKey 2390318) — https://www.gbif.org/occurrence/search?taxon_key=2390318&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273918 (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 niger Woodland, 1990 as Vulnerable (code VU). 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 69690275) — https://www.iucnredlist.org/species/69690275/0; GBIF IUCN Red List category endpoint (taxonKey 2390318) — https://api.gbif.org/v1/species/2390318/iucnRedListCategory. Accessed 2026-09-23.
Description and natural history (Wikipedia)
The black foxface was first formally described in 1990 by the ichthyologist David J. Woodland with the type locality given as Euakafa Island in the Vava'u Group of Tonga. This species is sometimes placed with the other four species of "foxfaced rabbitfishes" in a subgenus of the genus Siganus called Lo. The specific name niger means black, a reference to the dark colour of this species.
The black foxface, like almost all of the other rabbitfishes, has 13 spines and 10 soft rays in its dorsal fin and 7 spines and 9 soft rays in its anal fin. It grows to a total length of 22 cm. The overall colour is almost completely black but the pectoral fins are yellow as is the margin of the soft rayed part of the dorsal fin, the anal fin and the caudal fin. There is a broad white stripe on the gill cover which is overlain with a vermiculated pattern.
The black foxface is endemic to Tonga in the Western Pacific Ocean, although it is only common in the northernmost Tongan island group of Vava'u. It is found at depths between 2 and 15 m in the visvinity of drop offs at the edges of coral reefs. This species shows a preference for areas where there are staghorn or fire corals, and where there rubble mounds made up of flat and staghorn corals.
The black foxface lives in pairs as adults, the juveniles are thought to school. It feeds on macroalgae. They are known to change colour and pattern when alarmed. 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.
The black foxface appears in the aquarium trade. It is also targeted by spear fishers and the catch is sold fresh.
Source: Wikipedia: Black foxface — https://en.wikipedia.org/wiki/Black_foxface (CC BY-SA 4.0). Accessed 2026-09-23.
Frequently Asked Questions
Who is Black foxface (Siganus niger)?
It is a small marine rabbitfish in the family Siganidae, first formally described by Woodland in 1990. The species sits within the order Acanthuriformes and is found exclusively in the waters surrounding Tonga in the western Pacific.
What are Black foxface (Siganus niger)'s powers or ecological role?
Like other rabbitfish, it grazes on algae and detritus across coral-reef surfaces, helping limit algal overgrowth on the reef. It operates in relatively shallow water, typically between 2 and 15 metres depth.
Where does Black foxface (Siganus niger) live?
The species is endemic to Tonga, meaning no other location in the world is known to harbour it. Its entire natural range is confined to the western Pacific waters around that island nation.
How big does Black foxface (Siganus niger) get?
It reaches a maximum total length of roughly 22 centimetres, placing it among the smaller members of the rabbitfish family. Its body is supported by bony, ray-finned structures rather than cartilage, as is typical of its order.
Why is Black foxface (Siganus niger) important to conservation?
Because it exists only in Tongan waters, any localized threat—reef degradation, invasive species, or pollution—directly endangers the entire global population. Protecting Tonga's shallow reef habitats is therefore the single most critical factor for the species' long-term survival.
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