It is often caught incidentally by bottom trawl fisheries off South Africa, and may also be impacted by pollution from coastal development.

The onefin electric ray was described by German naturalist Johann Friedrich Gmelin in 1789, in the 13th edition of Systema Naturae.

The original spelling was probably rapensis, which modern taxonomists regard as a typesetting error as the etymology of capensis ("of the Cape [of Good Hope]") is far more reasonable.

Later sources have consistently used capensis, though to officially fix the specific epithet under that spelling would require a decision by the International Commission on Zoological Nomenclature (ICZN).

[2] In 1826, German naturalist Johann Jakob Kaup created the new genus Narke for this species, separating it from the other electric rays known at the time on the basis of its curved back and single dorsal fin.

The short and thick tail has a skin fold running along either side and terminates in a large triangular caudal fin with rounded corners, which is almost symmetrical above and below.

[7][9] The onefin electric ray is common off the Eastern and Western Cape Provinces of South Africa.

[9] Though not utilized economically, this ray is frequently caught as bycatch in bottom trawls in South African waters.