Blackfish (species: Actinopyga miliaris) in taxonomy (Lizard Island Field Guide)
Actinopyga miliaris

©Anne Hoggett: Actinopyga miliaris about 30 cm long in its elongate, undisturbed state on the reef flat, Lizard Island.

©Anne Hoggett: The same specimen of Actinopyga miliaris on the reef flat, Lizard Island, in its contracted state after being disturbed, now less than 20 cm long.

©Anne Hoggett: Anal teeth of the same specimen of Actinopyga miliaris on the reef flat, Lizard Island.
Kingdom Animalia
Phylum Echinodermata
Class Holothuroidea
Order Aspidochirotida
Family Holothuriidae
Genus Actinopyga
Species Actinopyga miliaris



Distinguishing features

All species of Actinopyga have distinct anal "teeth" that are visible in the field and none of them eject cuverian tubules when disturbed.

Actinopyga miliaris is black all over and is known as the Blackfish in the trepang trade. When disturbed, the body contracts to become shorter and thicker. The body wall is thick, firm and smooth and is covered with short, spaced papillae. Anal teeth are orange and relatively smooth. Cuverian tubules are not present.


  • Up to 35 cm (length, Purcell et al 2012)

Depth range

  • Up to 12 m (Purcell et al 2012)


Similar taxa


©Atlas of Living Australia: Australian distribution

Distribution and habitat preferences

Actinopyga miliaris is found mostly in shallow reef habitats around the Lizard Island group.


Has been observed spawning at Lizard Island: 4 pm, 18 Oct 2018.

Web resources


References that assist with identification

  • Cannon, L.R.G. and H. Silver (1986). Sea Cucumbers of Northern Australia Queensland Museum, Brisbane. LIRS catalog number 229.
  • Purcell, S.W., Y. Samyn and C. Conand (2012). Commercially important sea cucumbers of the world 150 pp., 30 pl. Food and Agriculture Organization of the United Nations, Rome.

Other references

  • Uthicke, S., T.D. O'Hara and M. Byrne (2004). Species composition and molecular phylogeny of the Indo-Pacific teatfish (Echinodermata: Holothurioidea) beche-de-mer fishery, Marine and Freshwater Research, 55: 837-848. LIRS catalog number 1034.