This species can be identified by its spade-shaped pectoral fin disc with concave anterior margins, long tail with well-developed skin folds along either side, and plain dark brown dorsal colouration.

Scottish naturalist John Richardson described the Tasmanian numbfish in an 1841 contribution to Proceedings of the Zoological Society of London.

Classifying the new species in the genus Narcine, he gave it the specific epithet tasmaniensis as the holotype, a female 36 cm (14 in) long, was collected from Port Arthur, Tasmania.

[2] In a 2012 phylogenetic study based on mitochondrial DNA, Narcine was found to be polyphyletic, with the Tasmanian numbfish belonging to a different lineage than the giant electric ray (N.

[7] Reaching a length of at least 47 cm (19 in), the Tasmanian numbfish has a trowel-shaped pectoral fin disc with a short, blunt snout and concave leading margins.

The teeth are small and diamond-shaped with pointed tips; they are arranged with a quincunx pattern into bands, which remain exposed when the mouth is closed.

[1] The Tasmanian numbfish is a fairly inactive species that spends long periods of time buried motionless in sediment.

It feeds primarily on polychaete worms (particularly those of the family Maldanidae) and crustaceans (including amphipods, decapods, and tanaids).

This dietary shift may reflect increasing experience with age, as polychaetes are burrowing animals and thus more difficult to locate and capture than crustaceans.

[1] The Tasmanian numbfish is frequently caught incidentally by trawlers of Australia's South East Trawl Fishery, which operate throughout its range.