Coffin ray

Coffin ray
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Superorder:	Batoidea
Order:	Torpediniformes
Family:	Hypnidae T. N. Gill, 1862
Genus:	Hypnos A. H. A. Duméril, 1852
Species:	H. monopterygius
Binomial name
Hypnos monopterygius (G. Shaw, 1795)
Range of the coffin ray[1]
Synonyms
Hypnos subnigrum Duméril, 1852 Lophius monopterygius Shaw, 1795

Hypnos monopterygius, also known as the coffin ray or Australian numbfish, is a species of electric ray endemic to Australia, where it is common in inshore waters shallower than 80 m (260 ft). It is the sole member of its genus Hypnos, and family Hypnidae. This small species typically reaches 40 cm (16 in) in length. Greatly enlarged pectoral fins and an extremely short tail, coupled with diminutive dorsal and caudal fins all concentrated towards the rear, give the coffin ray a distinctive pear-like shape. It is a varying shade of brown in colour above, and has tiny eyes and a large, highly distensible mouth.

The sluggish and nocturnal coffin ray frequents sandy or muddy habitats, where it can bury itself during daytime. Able to produce a powerful electric shock reaching 200 volts for attack and defense, it can deliver a severe – albeit non-fatal – shock to a human. This species is a voracious predator that feeds mainly on benthic bony fishes, often tackling fish approaching or exceeding itself in size. On occasion, it may also consume invertebrates and even small penguins and rats. Reproduction is aplacental viviparous, in which the developing embryos are nourished by yolk and maternally produced histotroph ("uterine milk"). The female gives birth to 4–8 pups during summer. Not valued commercially, it is very hardy and can usually survive being captured and discarded. The International Union for Conservation of Nature (IUCN) has listed this species under Least Concern, as its population does not seem threatened by human activity.