Common name: Coffin rays


An endemic Australian family with a single species distinguishable from other electric rays in having a pear-shaped disc and an extremely short tail, with only the caudal fin extending beyond the posterior edge of the pelvic fins; lateral skin folds absent; spiracles with a 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.

Cite this page as:
Martin F. Gomon & Dianne J. Bray, Coffin rays, HYPNIDAE in Fishes of Australia, accessed 15 Jul 2024,


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. (p. 1447, as Hypnos monopterygium)

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. (p. 103, as Hypnos monopterygium)

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 (p. 154, as Hypnos monopterygium)

Last, P.R. & Stevens, J.D. 1994. Sharks and Rays of Australia. Canberra : CSIRO Australia 513 pp. 84 pls (p. 372, as Hypnos monopterygium)

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