The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Siganus unimaculatus
Siganus unimaculatus
(blotched foxface)
Marine Fishes

Copyright Info
Siganus unimaculatus (Evermann and Seale, 1907)

Common name: blotched foxface

Synonyms and Other Names: Original combination: Lo unimaculatus; foxface rabbitfish, onespot rabbitfish

Taxonomy: available through www.itis.govITIS logo

Identification: Dorsal fin XIII (10).  Anal fin VII (9).  Pelvic fin II (3).  Pelvic fin spines and soft rays are interspersed (i.e., spines occur between rays), a trait unique to the family Siganidae.  Fin spines have lateral grooves containing venom glands.  Body mostly yellow.  Tubular snout.  Head with distinct black and white colour pattern (see photo, above).  Siganus unimaculatus has a large dark blotch on upper side below spinous portion of dorsal fin.

Similar species –Non-native: Siganus vulpinus distinguished by lack of black body spot; Siganus puellus distinguished by broken blue lines vertically on forebody and horizontally on rear. Lacks black body spot and second dark edge on gill cover.  Native: There are no rabbitfishes native to the Tropical Western Atlantic, though Spotfin Butterflyfish, Chaetodon occellatus, will occasionally show a dark body spot in its night coloration while lacking the dark face markings of S. unimaculatus.

Size: to 24 cm (Allen et al. 2003)

Native Range: SW Japan (Ryukyu Islands) and Philippines to NW Australia (Allen et al. 2003).

Interactive maps: Point Distribution Maps

Nonindigenous Occurrences: In Florida, a single individual was reported and subsequently captured off Dania Beach in September 2016 (L. Akins, personal communication).

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Siganus unimaculatus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†

Table last updated 5/18/2021

† Populations may not be currently present.

Ecology: Inhabits shallow coral reefs to depths of about 5 m.  Juveniles aggregate in large groups (up to several hundred individuals) but adults are mostly found in pairs.  Often shelter in staghorn corals.  Consume seaweeds, encrusting algae and some seagrasses.  Reportedly has large appetite and spends a great deal of time feeding.  From Allen et al. (2003); Woodland (1997).

Means of Introduction: Probably aquarium release.

Status: Reported from Florida. Eradicated.

Impact of Introduction: Unknown.  Rabbitfishes are venomous (similar to lionfish), and thus could be harmful to humans. Associations with federally listed staghorn corals could prove to be deleterious.

References: (click for full references)

Allen, G., R. Steene, P. Humann, and N. Deloach. 2003. Reef fish identification: tropical Pacific. New World Publications, Inc., Jacksonville, FL.

Woodland, D., 1997. Siganidae. Rabbitfishes (spinefoots). p. 3627-3650. In K.E. Carpenter and V. Niem (eds.) FAO Identification Guide for Fishery Purposes. The Western Central Pacific. 837 p.

Other Resources:

Author: Schofield, P.J.

Revision Date: 9/28/2016

Citation Information:
Schofield, P.J., 2021, Siganus unimaculatus (Evermann and Seale, 1907): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=3094, Revision Date: 9/28/2016, Access Date: 5/18/2021

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2021]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [5/18/2021].

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