Common name: blotched foxface
Synonyms and Other Names: Original combination: Lo unimaculatus; foxface rabbitfish, onespot rabbitfish
available through www.itis.gov
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).
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.
Table last updated 1/21/2022
† 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.
Revision Date: 9/28/2016
Schofield, P.J., 2022, 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: 1/21/2022
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.