Electric ray

Electric rays Temporal range: Eocene–Recent[1] PreꞒ Ꞓ O S D C P T J K Pg N
Marbled electric ray (Torpedo marmorata)
Lesser electric ray (Narcine bancroftii)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Superorder:	Batoidea
Order:	Torpediniformes F. de Buen, 1926
Families
Narcinidae Hypnidae Torpedinidae

The electric rays are a group of rays, flattened cartilaginous fish with enlarged pectoral fins. They are the order Torpediniformes.

They can produce an electric discharge, ranging from as little as 8 volts up to 220 volts depending on species.^[2] There are 69 species in four subfamilies.

These rays have battery-like electric organs on both sides of their heads, which can make a powerful electric shock. They use this shock to stun their prey and for their own self defense.^[1]

Electric rays are found from shallow coastal waters down to at least 1,000 metres (3,300 ft) depth. They are sluggish and slow moving, propelling themselves along with their tails, rather than using their disc-shaped bodies, as other rays do. They feed on invertebrates and small fish. They lie in wait for prey below the sand or other substrate, using their electricity to stun and capture it.^[2][3][4]

Classification

The electric rays are regarded as monophyletic,^[5] though in detail the group has been classified in several ways.^[5] This is one way the order can be classified.

• Family Narcinidae (numbfishes)
  • Subfamily Narcininae
  • Subfamily Narkinae (sleeper rays)
• Family Torpedinidae (torpedo electric rays)
  • Subfamily Hypninae (coffin rays)
  • Subfamily Torpedininae

The word torpedo comes from a genus of electric rays in the sub-family Torpedininae, namely Torpedo, which in turn comes from the Latin "torpere" (to be stiff or numb).

Related pages

• Electric fish

References

1. "Torpediniformes". FishBase. Ed. Ranier Froese and Daniel Pauly. February 2011 version. N.p.: FishBase, 2011.
2. Martin, R. Aidan. Electric Rays. ReefQuest Centre for Shark Research. Retrieved on October 12, 2008.
3. Stevens J. & Last P.K. (1998). Paxton J.R. & Eschmeyer W.N. (ed.). Encyclopedia of Fishes. San Diego: Academic Press. p. 66. ISBN 0-12-547665-5.
4. Hamlett, William C. (1999). Sharks, skates, and rays: the biology of elasmobranch fishes. Baltimore and London: JHU Press. ISBN 0-8018604-8-2.
5. Compagno, Leonard J.V. and Heemstra, Phillip C. (May 2007) "Electrolux addisoni, a new genus and species of electric ray from the east coast of South Africa (Rajiformes: Torpedinoidei: Narkidae), with a review of torpedinoid taxonomy". Smithiana, Publications in Aquatic Biodiversity, Bulletin 7: 15-49. Retrieved on October 22, 2008.