Coffin Ray, Hypnos monopterygius (Shaw & Nodder 1795)

Other Names: Australian Numbfish, Coffin Ray, Crampfish, Cramp-fish, Electric Ray, Numb Ray, Numbfish, Numb-fish, Numbie, Short-tail Electric Ray, Short-tailed Electric Ray, Torpedo

A Coffin Ray, Hypnos monopterygius, with parasitic marine leeches, at Bare Island, Botany Bay, New South Wales, 5 December 2014. Source: John Turnbull / Flickr. License: CC by Attribution-NonCommercial-ShareAlike


A small electric ray with a flattened pear-shaped disc, two dorsal fins and an extremely short tail, with only the caudal fin extending beyond the hind margin of the pelvic fins. An electric organ is located in each pectoral fin.

Although the Coffin Ray usually uses its electric organs to stun its prey, it can deliver a powerful shock to unsuspecting swimmers and divers.

These slow-moving rays usually lie buried in sandy or muddy bottoms.

A very active Coffin Ray (aka Numb Ray) swimming at Shark Point, Sydney New South Wales, October 2015.

A Coffin Ray at the wreck of the "Scottish Prince" on the Gold Coast, Queensland.

A Coffin Ray at Bawley Point, New South Wales.

Coffin Ray compilation

A Coffin Ray at Esperance

Cite this page as:
Bray, D.J. 2022, Hypnos monopterygius in Fishes of Australia, accessed 19 May 2024,

Coffin Ray, Hypnos monopterygius (Shaw & Nodder 1795)

More Info


Heron Island, Queensland, to about Mallacoota, Victoria, and from off Kingston, South Australia, to about Beagle Bay in The Kimberley, Western Australia.

Inhabits sandy and muddy areas in bays and estuaries. Individuals usually lie buried in the sediment, waiting for unsuspecting prey.


Disc pear-shaped, tail extremely short, only caudal fin extending beyond posterior edge of ventral fins; lateral skin folds absent; spiracles with crenulated edge; mouth arched anteriorly, widely distensible;  internasal flap narrow; teeth tricuspidate; 2 dorsal fins of similar size, bases adjacent, both above pelvic fins; caudal fin rounded.


To 60 cm total length.


Upper surface uniformly pale brown, reddish-brown or dark brown approaching black; spiracle folds white; underside yellowish.


Feeds mostly on fishes, crustaceans and polychaete worms. The Coffin Ray has an electric organ on each side of its body and delivers a powerful electric shock to stun its prey. Coffin rays can swallow large food items - including the occasional Little Penguin.


Females give birth to live young (viviparous), born at a length of 8-11 cm.


Occasionally taken as bycatch in commercial trawls.


  • IUCN Red List : Least Concern
  • Species Citation

    Lophius monopterygius Shaw & Nodder 1795, Nat. Miscell. 6: pl. 202, 203. Type locality: Australian seas.


    Bray, D.J. 2022


    Atlas of Living Australia

    Coffin Ray, Hypnos monopterygius (Shaw & Nodder 1795)


    Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Perth : Western Australian Museum 292 pp. 106 pls.

    Coleman, N. 1980. Australian Sea Fishes South of 30ºS. Lane Cove, NSW : Doubleday Australia Pty Ltd 309 pp.

    Compagno, L.J.V. & Last, P.R. 1999. Families Narkidae, Hypnidae, Torpedinidae. pp. 1443-1451 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 3 1397-2068 pp.

    Daley, R.K., Stevens, J.D., Last, P.R. & Yearsley, G.K. 2002. Field Guide to Australian Sharks & Rays. Hobart : CSIRO Marine Research 84 pp.

    Duméril, A.H.A. 1852. Monographie de la famille des torpédiniens, ou poissons plagiostomes électriques. Revue et Magasin de Zoologie (Paris) 2 4: 270-285 (described as Hypnos subnigrum, type locality Sydney, New South Wales)

    Gomon, M.F. 2008. Families Torpedinidae to Rhinobatidae. pp. 101-107 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

    Grant, E.M. 1975. Guide to Fishes. Brisbane : Queensland Government, Co-ordinator General’s Department 640 pp.

    Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.

    Hoschke, A., Whisson, G. & Moore, G.I. 2019. Complete list of fishes from Rottnest Island. pp. 150-161 in Whisson, G. & Hoschke, A. (eds). The Rottnest Island fish book. 2nd ed. Perth, Australia : Aqua Research and Monitoring Services.

    Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3)

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

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

    Kyne, P.M., Johnson, J.W., Courtney, A.J. & Bennett, M.B. 2005. New biogeographical information on Queensland chrondrichthyans. Memoirs of the Queensland Museum 50(2): 321-327

    Last, P.R. 1994. Families Torpedinidae, Rajiidae, Rhinobatidae. pp. 154-172 figs 132-149 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.

    Last, P.R. & Stevens, J.D. 1994. Sharks and Rays of Australia. Canberra : CSIRO Australia 513 pp. 84 pls.

    Last, P.R. & Stevens, J.D. 2009. Sharks and Rays of Australia. Collingwood : CSIRO Publishing Australia 2, 550 pp.

    Lisney, T.J. (SSG Australia & Oceania Regional Workshop, March 2003) 2003. Hypnos monopterygius. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. <>. Downloaded on 4 March 2012.

    Randall, J.E., Allen, G.R. & Steene, R. 1990. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 507 pp. figs.

    Randall, J.E., Allen, G.R. & Steene, R. 1997. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 557 pp. figs.

    Shaw, G. & Nodder, F.P. 1795. The Naturalist's Miscellany, or coloured figures of natural objects; drawn and described from nature. London Vol. 6 pls 196–230, unnumbered pages. [for date of publication Sherborn, C.D. 1895. On the dates of Shaw and Nodder's Naturalist's Miscellany. Annals and Magazine of Natural History 6 15(88): 375–376 See ref at BHL

    Stead, D.G. 1963. Sharks and Rays of Australian Seas. Sydney : Angus & Robertson 211 pp. 63 figs.

    Whitley, G.P. 1931. New names for Australian fishes. The Australian Zoologist 6(4): 310-334 1 fig. pls 25-27 (as Hypnos monopterygium)

    Whitley, G.P. 1940. Illustrations of some Australian fishes. The Australian Zoologist 9(4): 397-428 figs 1-45 pls 30-31 (as Hypnarche monopterygium)

    Quick Facts

    CAAB Code:37028001

    Conservation:IUCN Least Concern

    Danger:Produces electric shocks

    Depth:4-220 m

    Habitat:Sandy, muddy bottoms

    Max Size:60 cm TL


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