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

The Eastern Smooth Boxfish is commonly seen washed up on beaches in south eastern Australia. The hard 'discus-like' carapace is quite distinctive.

Standard Common Name

Eastern Smooth Boxfish

Alternative Name/s

Blue Boxfish, Freckled Boxfish, Golden Boxfish, Polled Boxfish, Robust Box-fish, Robust Boxfish, White-barred Boxfish


The Eastern Smooth Boxfish has a hard carapace that is covered with a pattern of triangles and low bumps. Adults have a strong ridge along the dorsal and ventral midlines. There are weaker ridges passing over the eyes and under the pectoral fins. Juveniles are nearly spherical.

The species has eyes high on the head and its dorsal and anal fins positioned posteriorly and opposite each other.

The colouration of the Eastern Smooth Boxfish changes with growth. Tiny juveniles are completely yellow. As the fish ages it develops brown spots. Large males are blue with golden sides.

Size range

The Eastern Smooth Boxfish grows to 35 cm in length.


The species occurs from southern Queensland to Bass Strait.  Eastern Smooth Boxfish are commonly washed up on sandy beaches in south eastern Australia. Beach walkers often see dried fish while walking along the high tide line.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums.  Source: Atlas of Living Australia.

Anoplocapros inermis

Distribution by collection data

Ozcam map of Eastern Smooth Boxfish specimens in the Australian Museums.

What does this mean?


It is known from depths of 10 m to 300 m in coastal reefs and harbours.

Danger to humans and first aid

As a general rule Boxfishes generally should not be eaten. A toxin (ostracitoxin) is present in the mucous. In some species this can be secreted when the fish is stressed.



What does this mean?


  1. Edgar, G.J. 1997. Australian Marine Life: the plants and animals of temperate waters. Reed Books. Pp. 544.
  2. Kuiter, R.H. in Gomon, M..F, Glover, C.J.M. & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
  3. Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
  4. Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433. Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.

Mark McGrouther , Collection Manager, Ichthyology
Last Updated:

Tags Fishes, Ichthyology, Eastern Smooth Boxfish, Anoplocapros inermis, Ostraciidae, blue, gold, green, yellow, deep-boded, 30 cm - 1 m, dots/spots, intertidal, marine, adult,