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

Scientific name: Anoplocapros inermis
Alternative name/s:
Blue Boxfish, Freckled Boxfish, Golden Boxfish, Polled Boxfish, Robust Box-fish, Robust Boxfish, White-barred Boxfish
  • Author(s)
    Mark McGrouther
  • Updated
    11/03/21
  • Read time
    2 minutes
Anoplocapros inermis Click to enlarge image
Eastern Smooth Boxfish at a depth of 9 m, Oak Park, Sydney, New South Wales, August 1998. Image: E. Schlögl
© E. Schlögl

Fast Facts

  • Classification
    Genus
    Anoplocapros
    Species
    inermis
    Family
    Ostraciidae
    Order
    Tetraodontiformes
    Class
    Actinopterygii
    Subphylum
    Vertebrata
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    The Eastern Smooth Boxfish grows to 35 cm in length.

Introduction

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

Identification

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.

Anoplocapros inermis

An Eastern Smooth Boxfish washed up on the beach, Seven Mile Beach National Park, south of Gerroa, New South Wales, March 2008.

Image: M. Joyce
© M. Joyce

Habitat

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

Distribution

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.

Distribution data sourced from the Atlas of Living Australia

Danger to humans

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.

References

  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.