Blackblotch Foxface, Siganus unimaculatus (Evermann & Seale 1907)

Other Names: Black-blotch Fox-face, Blotched Foxface, One Spot Foxface

A Blackblotch Foxface, Siganus unimaculatus, at Pamilacan, Philippines, May 2017. Source: zsispeo / Flickr. License: CC By Attribution-NonCommercial-ShareAlike

A bright yellow rabbitfish with the head and anterior body white, a black band from the mouth to the dorsal-fin origin, a second black band running from the shoulder area to the breast region, and an irregular black spot or blotch on the middle to rear of the upper side.

Rabbitfish have stout venomous fin spines, and may cause a very painful sting.

Video of Blackblotch Spotface in the Shinagawa Public Aquarium, Japan.
Video of a Blackblotch Spotface in an aquarium.

Cite this page as:
Dianne J. Bray, Siganus unimaculatus in Fishes of Australia, accessed 20 Jun 2024,

Blackblotch Foxface, Siganus unimaculatus (Evermann & Seale 1907)

More Info


Recorded in Australia from Rowley Shoals off north Western Australia. The species occurs elsewhere in the Western Pacific. Inhabits rich coral areas in lagoons and on outer reefs, and among staghorn corals. Small juveniles occur in very large schools, while larger juveniles and adults are often seen in pairs.


Dorsal fin XIII, 10; Anal fin VII, 9; Pectoral fin 16-17; scale rows above lateral line 16-19; Vertebrae 13. 
Body depth 2.1-2.4 in SL; preopercular angle 109°-119°; cheek squamation variable cheek, usually scaled with 7-10 rows below middle of eye, occasionally only a few scattered scales present below eye; a triangular area from lower edge of orbit to angle of mouth always fully scaled; midline of thorax fully scaled.
Fin spines stout, pungent, and venomous; caudal peduncle only slightly incised; caudal fin emarginate.


Herbivore - feeds on algae.

Similar Species

The Blackbloth Spotface differs from the similar Foxface Rabbitfish, Siganus vulpinus, in having a dark spot or irregular blotch on the upper side.


The specific name unimaculatus refers to the spot or blotch on the side of the body.

Species Citation

Lo unimaculatus Evermann & Seale, 1907, Bull. Bur. Fish. (U.S.) for 1906 26: 98, fig. 19. Type locality: Bacon, Albany Gulf, Philippines.


Dianne J. Bray


Australian Faunal Directory

Blackblotch Foxface, Siganus unimaculatus (Evermann & Seale 1907)


Allen, G.R. & Erdmann, M.V. 2012. Reef fishes of the East Indies. Perth : Tropical Reef Research 3 vols, 1260 pp.

Borsa, P., Lemer, S. and Aurelle, D. Patterns of lineage diversification in rabbitfishes. Molecular Phylogenetics and Evolution 44: 427-435.

Evermann, B.W. & Seale, A. 1907. Fishes of the Philippine Islands. Bulletin of the Bureau of Fisheries (U.S.) for 1906 26: 49-110 figs 1-22

Gawel, M. & Woodland, D.J. 1974. Siganus (Lo) uspi, a new species from Fiji; and a comparison with the nominal species S. vulpinus and S. unimaculatus. Copeia 1974(4): 855-861.

Kuiter, R.H. & Debelius, H. 2001. Surgeonfishes, Rabbitfishes and Their Relatives. A comprehensive guide to Acanthuroidei. Chorleywood, U.K. : TMC Publishing 208 pp.

Kuriiwa, K., Hanzawa, N., Yoshino, T., Kimura, S. & Nishida, M. 2007. Phylogenetic relationships and natural hybridization in rabbitfishes (Teleostei: Siganidae) inferred from mitochondrial and nuclear DNA analyses. Molecular Phylogenetics and Evolution 45: 69-80.

Nanami, A. 2015. Pair formation, home range, and spatial variation in density, size and social status in blotched foxface Siganus unimaculatus on an Okinawan coral reef. PeerJ 3:e1280 Open Access
Woodland, D.J. 1990. Revision of the fish family Siganidae with descriptions of two new species and comments on distribution and biology. Indo-Pacific Fishes 19: 1-136 figs 1-23, 11 pls

Woodland, D.J. 2001. Siganidae. pp. 3627-3650 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218.

Quick Facts

CAAB Code:37438015

Danger:Venomous spines

Depth:1-30 m

Habitat:Reef associated

Max Size:24 cm TL

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Species Maps

CAAB distribution map