year=2011|month=February}}}}| image = Torpedo marmorata2.jpg| image_caption = Marbled electric ray(Torpedo marmorata)| image2 = Fish4345 - Flickr - NOAA Photo Library.jpg| image2_caption = Lesser electric ray(Narcine bancroftii)| taxon = Torpediniformes

Don Fernando de Buen y Lozano>F. de Buen, 1926| subdivision_ranks = Families| subdivision =

}}The electric rays are a group of rays, flattened cartilaginous fish with enlarged pectoral fins, composing the order Torpediniformes {{IPAc-en|t|É”r|'|p|E|d|áµ»|n|áµ»|f|É”r|m|iË|z}}. They are known for being capable of producing an electric discharge, ranging from 8 to 220 volts, depending on species, used to stun prey and for defense.WEB, Martin, R. Aidan,weblink Electric Rays, ReefQuest Centre for Shark Research, 12 October 2008, 15 October 2008,weblink" title="web.archive.org/web/20081015174241weblink">weblink live, There are 69 species in four families.Perhaps the best known members are those of the genus Torpedo. The torpedo undersea weapon is named after it. The name comes from the Latin , 'to be stiffened or paralyzed', from the effect on someone who touches the fish.ENCYCLOPEDIA, Kidd, D. A., Collins Latin Gem Dictionary: Latin-English, English-Latin, 1973, Collins Latin Gem Dictionary, Collins, London, 0-00-458641-7, Torpedo,

Description

Electric rays have a rounded pectoral disc with two moderately large rounded-angular (not pointed or hooked) dorsal fins (reduced in some Narcinidae), and a stout muscular tail with a well-developed caudal fin. The body is thick and flabby, with soft loose skin with no dermal denticles or thorns. A pair of kidney-shaped electric organs are at the base of the pectoral fins. The snout is broad, large in the Narcinidae, but reduced in all other families. The mouth, nostrils, and five pairs of gill slits are underneath the disc.BOOK, Hamlett, William C., Sharks, Skates, and Rays: The Biology of Elasmobranch Fishes, JHU Press, 1999, Baltimore and London, 0-8018-6048-2, Electric rays are found from shallow coastal waters down to at least {{convert|1000|m|ft|abbr=on}} deep. They are sluggish and slow-moving, propelling themselves with their tails, not by using their pectoral fins 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.BOOK, Stevens, J., Last, P. K., Paxton, J. R., Eschmeyer, W. N., 1998, Encyclopedia of Fishes, Academic Press, San Diego, 66, 0-12-547665-5,

Relationship to humans

History of research

The electrogenic properties of electric rays have been known since antiquity, although their nature was not understood. The ancient Greeks used electric rays to numb the pain of childbirth and operations. In his dialogue Meno, Plato has the character Meno accuse Socrates of "stunning" people with his puzzling questions, in a manner similar to the way the torpedo fish stuns with electricity.(Wikisource:Meno) Scribonius Largus, a Roman physician, recorded the use of torpedo fish for treatment of headaches and gout in his Compositiones Medicae of 46 AD.BOOK, Theodore Holmes Bullock, Carl D. Hopkins, Richard R. Fay, Electroreception,weblink 28 September 2006, Springer Science & Business Media, 978-0-387-28275-6, 6, In the 1770s the electric organs of the torpedo ray were the subject of Royal Society papers by John Walsh,JOURNAL, Walsh, John, John Walsh (scientist), 1773, On the Electric Property of the Torpedo: in a Letter to Benjamin Franklin, Philosophical Transactions of the Royal Society of London, 64, 461â€“480, and John Hunter.JOURNAL, Hunter, John, John Hunter (surgeon), 1773, Anatomical Observations on the Torpedo, Philosophical Transactions of the Royal Society of London, 63, 481â€“489, JOURNAL, Hunter, John, 1775, An account of the Gymnotus electricus, Philosophical Transactions of the Royal Society of London, 65, 395â€“407, These appear to have influenced the thinking of Luigi Galvani and Alessandro Volta â€“ the founders of electrophysiology and electrochemistry.JOURNAL, Alexander, Mauro, The role of the voltaic pile in the Galvani-Volta controversy concerning animal vs. metallic electricity, Journal of the History of Medicine and Allied Sciences, 1969, XXIV, 2, 140â€“150, 10.1093/jhmas/xxiv.2.140, 4895861, WEB, Edwards, Paul, A Correction to the Record of Early Electrophysiology Research on the 250 th An- niversary of a Historic Expedition to ÃŽle de RÃ©,weblink HAL open-access archive, 6 May 2022, 10 November 2021, Henry Cavendish proposed that electric rays use electricity; he built an artificial ray consisting of fish shaped Leyden jars to successfully mimic their behaviour in 1773.WEB, Shock and Awe: The Story of Electricity, Al-Khalili, Jim, Jim Al-Khalili, BBC,weblink 9 June 2022,

In folklore

The torpedo fish, or electric ray, appears continuously in premodern natural histories as a magical creature, and its ability to numb fishermen without seeming to touch them was a significant source of evidence for the belief in occult qualities in nature during the ages before the discovery of electricity as an explanatory mode.JOURNAL, Copenhaver, Brian P., A tale of two fishes: Magical objects in natural history from antiquity through the scientific revolution, Journal of the History of Ideas, September 1991, 52, 3, 373â€“398, 10.2307/2710043, 2710043, 11622951,

Bioelectricity

{{further|Electric fish}}{{multiple image|image1=Torpedo electric organs.jpg|caption1=Position of the two electric organs|image2=Elektroplax Rochen.png|caption2=Diagram of structure of electric organs and stacked electrocytes|total_width=400}}The electric rays have specialised electric organs. Many species of rays and skates outside the family have electric organs in the tail; however, the electric ray has two large kidney-shaped electric organs on each side of its head, where current passes from the lower to the upper surface of the body. The nerves that signal the organ to discharge branch repeatedly, then attach to the lower side of each plaque in the batteries. These are composed of hexagonal columns, closely packed in a honeycomb formation. Each column consists of 500 to more than 1000 plaques of modified striated muscle, adapted from the branchial (gill arch) muscles.BOOK, Fishes of the Western North Atlantic, Part 2, Bigelow, H. B., Schroeder, W. C., Sears Foundation for Marine Research, Yale University, 1953, 80â€“104, BOOK, A Living Bay: the Underwater World of Monterey Bay, Langstroth, L., Newberry, T., amp, University of California Press, 2000, 0-520-22149-4, 222, In marine fish, these batteries are connected as a parallel circuit, whereas freshwater batteries are arranged in series. This allows freshwater rays to transmit discharges of higher voltage, as freshwater cannot conduct electricity as well as saltwater.BOOK, Springer, 978-3-540-23735-8, 1050â€“1056, Marc D. Binder, Nobutaka Hirokawa, Uwe Windhorst, Kramer, Bernd, Encyclopedia of Neuroscience, Electric Organ Discharge, Berlin, Heidelberg, 2012-03-25, 2008,weblink With such a battery, an electric ray may electrocute larger prey with a voltage of between 8 volts in some narcinids to 220 volts in Torpedo nobiliana, the Atlantic torpedo.BOOK, International Wildlife Encyclopedia, Burton, R., Third, Marshall Cavendish, 2002, 0-7614-7266-5, 768,

Systematics

The 60 or so species of electric rays are grouped into 12 genera and two families.BOOK, Fishes of the World,weblink limited, Nelson, J.S., fourth, John Wiley, 2006, 0-471-25031-7, 69â€“82, The Narkinae are sometimes elevated to a family, the Narkidae. The torpedinids feed on large prey, which are stunned using their electric organs and swallowed whole, while the narcinids specialize on small prey on or in the bottom substrate. Both groups use electricity for defense, but it is unclear whether the narcinids use electricity in feeding.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.

Family Narcinidae (numbfishes)
- Subfamily Narcininae
  - Genus Benthobatis
  - Genus Diplobatis
  - Genus Discopyge
  - Genus Narcine
- Subfamily Narkinae (sleeper rays)
  - Genus Crassinarke
  - Genus Electrolux
  - Genus Heteronarce
  - Genus Narke
  - Genus Temera
  - Genus Typhlonarke
Family Hypnidae (coffin rays)
- Subfamily Hypninae (coffin rays)
  - Genus Hypnos
Family Torpedinidae (torpedo electric rays)
- Subfamily Torpedininae
  - Genus Tetronarce
  - Genus Torpedo

References

- content above as imported from Wikipedia
- "Electric ray" does not exist on GetWiki (yet)
- time: 7:39pm EDT - Fri, Apr 26 2024

[ this remote article is provided by Wikipedia ]

CONNECT

GetWiki

Electric ray

Description

Relationship to humans

History of research

In folklore

Bioelectricity

Systematics

See also

References