Bass Groper, Polyprion americanus (Bloch & Schneider 1801)

Other Names: Groper, Hapuka, Hapuka Cod, Hapuku, Longnose Hapuku, Moeone, Sea Bass, Stone Bass, Wreckfish

A Bass Groper, Polyprion americanus, from eastern Tasmania. Source: Chris Rowley / Museums Victoria. License: CC BY Attribution


A large, long-lived perch-like fish with a relatively deep body and a rounded tail. Adults are dark brown to slate-grey with whitish tips o the tail lobes. Juveniles have an irregular mottled pattern with a whitish margin to the tail.

A highly regarded food fish.

Video of Polyprion americanus in the Atlantic.

Cite this page as:
Bray, D.J. 2018, Polyprion americanus in Fishes of Australia, accessed 17 Jun 2024,

Bass Groper, Polyprion americanus (Bloch & Schneider 1801)

More Info


Widespread in southern Australia from off Brunswick Heads, New South Wales, about Fraser Island (Queensland) to north of Perth (Western Australia), including Tasmania.

Elsewhere the species is widespread with a discontinuous distribution in the Atlantic, Indian and Pacific Oceans, including New Zealand. 

Adults usually inhabit deep rocky reefs at 100–900 m (most commonly at 350-700 m), juveniles to 60 cm are pelagic, associating with floating debris.


Dorsal fin XI-XII, 11-12; Anal fin III, 9-10; Caudal fin 17; Pectoral fin 15-18; Pelvic fin I, 5; Lateral line (incl. scales onto caudal fin) 70-87; Vertebrae 13 + 14.

Body depth 35.3-43.3% SL; head length 37.6-44.4% SL; bony orbit diameter 18.2-21.1% HL; upper jaw 39.8-50.5% HL, lower jaw protruding; posterior margin of preopercle and subopercle finely serrate (juveniles with strong serrations on orbitals, supraoccipital crest, opercular ridge, posttemporal, supracleithrum, cleithrum, and pelvic and anal spines).


Reaches 2 m in length and 100 kg in weight, commonly to 80 cm and 15 kg.


Adults are uniform dark brown to slate grey on sides, caudal angles white; juveniles brownish grey, mottled with irregular pale white to yellow markings, caudal with white margin.


Carnivore - feeds on other fishes and invertebrates.


The sexes are separate and fertilisation is external. Bass Groper spawn in mid-winter, possibly after a substantial migration to the spawning grounds. 


Taken as bycatch on deep longlines in the Blue-eye Trevalla fishery in Australian waters.


The Bass Groper is threatened by over-fishing in some areas and listed by the IUCN as Data Deficient.

Species Citation

Amphiprion americanus Bloch & Schneider, 1801, Syst. Ichth.: 205. Type locality: "America".


Bray, D.J. 2018


Australian Faunal Directory

Bass Groper, Polyprion americanus (Bloch & Schneider 1801)


Ball, A.O., Sedberry, G.R., Zatcoff, M.S., Chapman, R.W. & Carlin, J.L. 2000. Population structure of the wreckfish Polyprion americanus determined with microsatellite genetic markers. Marine Biology 137: 1077-1090.

Hutchins, J.B. & Swainston, R. 1986. Sea Fishes of Southern Australia. Complete field guide for anglers and divers. Perth : Swainston Publishing 180 pp.

Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs (as Polyprion moeone)

Peres, M.B. & Klippel, S. 2003. Reproductive biology of southwestern Atlantic wreckfish, Polyprion americanus (Teleostei: Polyprionidae). Environ. Biol. Fish. 68: 163-173.

Roberts, C. D. 1986. Systematics of the percomorph fish genus Polyprion Oken, 1817. Ph.D. dissertation, Victoria University of Wellington. 283 pp.

Roberts, C.D. 1989. Reproductive mode in the percomorph fish Polyprion Oken. J. Fish Biol. 34(1):1-10.

Roberts, C.D. 2015 165 Family Polyprionidae, pp. 1175-1177, in Roberts, C.D., Stewart, A.L. & Struthers, C.D. (eds). The Fishes of New Zealand. Wellington : Te Papa Press Vol. 4 pp. 1153-1748.

Roberts, C.D. & Gomon, M. F. 2008. Families Polyprionidae, Serranidae and Callanthiidae. pp. 534-549 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Sadovy, Y. (Grouper & Wrasse Specialist Group). 2003. Polyprion americanus. The IUCN Red List of Threatened Species 2003: e.T43972A10845280. Downloaded on 25 July 2018.

Sedberry, G.R., Carlin, J.L., Chapman, R.W. & Eleby, B. 1996. Population structure in the pan-oceanic wreckfish, Polyprion americanus (Teleostei: Polyprionidae), as indicated by mtDNA variation. Journal of Fish Biology 49(Supplement A): 318-329.

Yearsley, G.K., Last, P.R. & Ward, R.D. (eds) 1999. Australian Seafood Handbook. Hobart : CSIRO Marine Research 460 pp.

Quick Facts

CAAB Code:37311170

Conservation:IUCN Data Deficient

Depth:100-900 metres

Fishing:Commercial/recreational fish

Habitat:Deep rocky reefs

Max Size:210 cm TL

Species Image Gallery

Species Maps

CAAB distribution map