Eastern Smooth Boxfish, Anoplocapros inermis (Fraser-Brunner 1935)

Other Names: Chubby Basketfish, Freckled Boxfish, Golden Boxfish, Polled Boxfish, Robust Boxfish, Robust Box-fish, White-barred Boxfish

An Eastern Smooth Boxfish, Anoplocapros inermis, at Little Beach, Port Stephens, New South Wales, 12 December 2016. Source: John Turnbull / Flickr. License: CC by Attribution-NonCommercial

A pale yellow to brownish boxfish with large dark yellowish to brown spots. As the males mature, they lose the spots and become pale blue with a yellow hue on the body and pale blue fins.

Video of an Eastern Smooth Boxfish at Bawley Point, New South Wales.

Boxfishes should not be eaten. Although the flesh is not poisonous, a mucous toxin, ostracitoxin, is present in some species - which the fish may secrete from its skin if stressed or threatened.

Cite this page as:
Bray, D.J. 2021, Anoplocapros inermis in Fishes of Australia, accessed 25 May 2024, https://fishesofaustralia.net.au/home/species/831

Eastern Smooth Boxfish, Anoplocapros inermis (Fraser-Brunner 1935)

More Info


Known from temperate waters of southeastern Australia from southern Queensland to Western Port (Victoria). The species occurs elsewhere in the Solomon Islands and South Africa. Inhabits coastal and offshore reefs at depths of 2-300 m in Australia.


Dorsal fin 10-11; Anal fin 10-11; Pectoral fin 12; Caudal fin 11.  

Body with two series of bony plates encircling the caudal peduncle, the anterior ring incomplete laterally, the posterior ring continuous, plates covered with rough tubercles.


To a maximum standard length of 35 cm SL.


Body pale yellow to brown above the ventrolateral ridge, bone-white below; dorsal and lateral sides of body with large dark yellow to dark brown spots; fins clear. As males mature, they lose the spots and become pale blue with a yellow hue on the body; fins pale blue.


Carnivore - feeds on invertebrates such as crabs.


The sexes are separate and fertilization is external. Eggs and larvae are pelagic.


Although of no interest to fisheries, the Eastern Smooth Boxfish is taken as by-catch in commercial trawls.


IUCN Red List Status (2011): Least Concern


Although the flesh is not poisonous, a mucous toxin, ostracitoxin, is present in boxfishes and some species can secrete the poison under stress. The toxin kills other fish, and eventually the boxfish themselves if exposed to it. As the precise location of this toxin in all species is not fully understood, boxfish should be considered potentially toxic to humans and their consumption as food should be avoided.

Similar Species

The Eastern Smooth Boxfish has long been confused with The Western Smooth Boxfish, Anoplocapros amygdaloides. A. inermis differs in having a convex dorsal profile, the caudal peduncle partially encircled by bony plates just in front of caudal fin, and the dorsal and lateral sides plain, or with yellow to brown spots. A. amygdaloides has a straight dorsal profile, the caudal peduncle completely encircled by bony plates just in front of caudal fin, and the dorsal and lateral sides with nearly black spots.

Species Citation

Strophiurichthys inermis Fraser-Brunner, Ann. Mag. Nat. Hist. 10 16(29): 319. Type locality:


Bray, D.J. 2021


Atlas of Living Australia

Eastern Smooth Boxfish, Anoplocapros inermis (Fraser-Brunner 1935)


Fraser-Brunner, A. 1935. Notes on the plectognath fishes. II. A synopsis of the genera of the family Ostraciontidae. Annals and Magazine of Natural History 10 16(29): 313-320 1 fig.

Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp.

Kuiter, R.H. 1994. Family Aracanidae. pp. 892-902, figs 788-794 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs.

Kuiter, R.H. 1996. Guide to sea fishes of Australia. A comprehensive reference for divers and fishermen. Sydney, NSW, Australia : New Holland Publishers, 434 pp.

Matsuura, K. 2008. Family Ostraciidae (pp. 842-948). In: Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Matsuura, K., Amaoka, K. & Carpenter, K.E. 2020. Anoplocapros inermis. The IUCN Red List of Threatened Species 2020: e.T154771A162979119. https://dx.doi.org/10.2305/IUCN.UK.2020-1.RLTS.T154771A162979119.en. Downloaded on 25 May 2021.

May, J.L. & Maxwell, J.G.H. 1986. Trawl fish from temperate waters of Australia. CSIRO Division of Fisheries Research, Tasmania. 492 pp.

Quick Facts

CAAB Code:37466002

Conservation:IUCN Least Concern

Depth:2–300 m

Habitat:Reef associated

Max Size:35 cm SL

Species Image Gallery

Species Maps

CAAB distribution map