Tetronarce

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Classis: Chondrichthyes
Subclassis: Elasmobranchii
Superordo: Rajomorphii
Ordo: Torpediniformes

Familia: Torpedinidae
Genus: Tetronarce
Species: T. californica – T. cowleyi – T. fairchildi – T. formosa – T. macneilli – T. nobiliana – T. peruana – T. puelcha – T. tokionis – T. tremens
Name

Tetronarce Gill, 1862

Type species: Torpedo occidentalis Storer, 1843

Etymology: tetra- (= four), referring, according to Gill (1895), to “four-sided form” of T. occidentalis (= nobiliana), perhaps an allusion to how the ray’s disc (two pectoral fins) and two pelvic fins appear as four sides (or lobes) when seen from above (Marcelo R. de Carvalho, pers. comm.); narce, from narke (= numbness), an ancient Greek word used for any electric fish, based on their ability to cause a numbing sensation [Gill attempted to change spelling to Tetranarke in 1895, saying Tetronarke was “purely a printer’s blunder,” but original spelling is retained]. From The ETYFish Project.
References

Gill, T. N. 1862. Analytical synopsis of the order of Squali; and revision of the nomenclature of the genera. Annals of the Lyceum of Natural History of New York, 7 (32): 367*-370*, 371-408. [Pp. 367-370 duplicated in preceding article. Read 16 Dec. 1861, probably published early 1862. Genera date to this article, also treated on pp.409-413. Both articles combined as separate, pp. 1-47p] From Catalog of FishesDOI: 10.1111/j.1749-6632.1862.tb00166.x Reference page.

Tetronarce is a genus of rays, commonly known as electric rays. They are slow-moving bottom-dwellers capable of generating electricity as a defense and feeding mechanism. Tetronarce species tend to attain a much larger size (up to 180 cm TL) than Torpedo species, which are usually small to moderate sized (range from 25 to 80 cm TL) electric rays.[1]
Species

There are currently nine recognized species in this genus:[1]

Image	Name	Common name	Distribution
	Tetronarce californica Ayres, 1855	Pacific electric ray	northeastern Pacific Ocean from Baja California to British Columbia.
	Tetronarce cowleyi Ebert, D. L. Haas & M. R. de Carvalho, 2015 [2]	Cowley's torpedo ray	around southern Africa, from Walvis Bay, Namibia to Algoa Bay, Eastern Cape, South Africa
	Tetronarce fairchildi F. W. Hutton, 1872	New Zealand torpedo	New Zealand
	Tetronarce formosa D. L. Haas & Ebert, 2006	Taiwan torpedo	Northwest Pacific: Taiwan.
	Tetronarce macneilli Whitley, 1932	Shorttail torpedo	southern Australia from Port Hedland to the Swain Reefs
	Tetronarce nobiliana Bonaparte, 1835	Atlantic torpedo	Atlantic Ocean, from Nova Scotia to Brazil in the west and from Scotland to West Africa and off southern Africa in the east
	Tetronarce puelcha Lahille, 1926	Argentine torpedo	Argentina, Brazil, and Uruguay.
	Tetronarce tokionis S. Tanaka (I), 1908	Trapezoid torpedo	Japan and Taiwan.
	Tetronarce tremens F. de Buen, 1959	Chilean torpedo	Chile, Colombia, Costa Rica, Ecuador, and Peru.

References

Carvalho, M.R. de. (2015): Torpedinidae. In : Heemstra, P.C., Heemstra, E. & Ebert, D.A. (Eds.), Coastal Fishes of the Western Indian Ocean. Vol. 1. South African Institute for Aquatic Biodiversity, Grahamstown, South Africa. In press.
Ebert, D.A., Haas, D.L. & de Carvalho, M.R. (2015): Tetronarce cowleyi, sp. nov., a new species of electric ray from southern Africa (Chondrichthyes: Torpediniformes: Torpedinidae). Zootaxa, 3936 (2): 237–250.