''Torpedo'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gra ...

, commonly known as electric rays, torpedo rays, or torpedoes. They are slow-moving bottom-dwellers capable of generating

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

as a defense and feeding mechanism. The

naval A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval warfare, naval and amphibious warfare; namely, lake-borne, riverine, littoral zone, littoral, or ocean-borne combat operations and ...

weapon A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...

known as the

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ...

was named after this genus, whose own name is derived from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word meaning 'numb' or 'paralysed', presumably the sensation one would feel after experiencing the ray's electric shock.

Electricity

The largest

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

is the

Gulf torpedo The Gulf torpedo (''Torpedo sinuspersici'') or variable electric ray, is a species of electric ray in the family Torpedinidae. It is found in the Indian Ocean, but may represent a species flock of several local endemic species. It is distinguish ...

, ''Torpedo sinuspersici'', which can grow to a weight of . Electric rays have patches of modified

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...

cells called electroplaques that make up an

electric organ An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the pump organ, harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has sinc ...

. These generate an electric gradient, similar to the normal

electric potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as the amount of work energy needed to move a unit of electric charge from a reference point to the specific point in ...

across most

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

s, but amplified greatly by its concentration into a very small area. The

can be stored in the tissues, which act as a

battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...

. The battery can be discharged in pulses. A ray can emit a shock into the body of a prey animal to stun it and make it easier to capture and eat, or into the body of a predator.

Use in neurobiological research

The torpedo electric organ, being composed of modified muscle cells, has proven highly useful in the

neurobiological Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developme ...

study of the neuromuscular junction. For example,

agrin Agrin is a large proteoglycan whose best-characterised role is in the development of the neuromuscular junction during embryogenesis. Agrin is named based on its involvement in the aggregation of acetylcholine receptors during synaptogenesis. ...

was first isolated from ''Torpedo''.

Ancient remedy

Scribonius Largus Scribonius Largus (c. 1-c. 50) was the court physician to the Roman emperor Claudius. About 47 AD, at the request of Gaius Julius Callistus, the emperor's freedman, he drew up a list of 271 prescriptions (''Compositiones''), most of them his own, ...

, a first century physician, advised the use of a live torpedo as a headache remedy. He stated, "Headache even if it is chronic and unbearable is taken away and remedied forever by a live torpedo placed under the spot that is in pain."

Description

Torpedo rays are flat like other rays, disc-shaped, with

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s that vary in length. Their mouths and

gill slit Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In con ...

s are located on their undersides. Males have

clasper In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating. Male cartilaginous fish have claspers formed from the posterior portion of their pelvic fin which serve to channel semen into the female's c ...

s near the base of the tail. Females are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

, meaning they form eggs but do not lay them. The young "hatch" within her body and she bears them live.

Species

There are currently 13 recognized species in this genus: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.'' * '' Torpedo adenensis'' M. R. de Carvalho, Stehmann & Manilo, 2002 (Aden Gulf torpedo) * '' Torpedo alexandrinsis''

Mazhar The ''mazhar'' ( ar, مزهر; plural ''mazāhar'', مزاهر) is a large, heavy tambourine used in Arabic music. The mazhar's frame is generally made out of wood. Its single head is considerably thicker than that of the '' riq'', its smaller ...

, 1987 (Alexandrine torpedo) * ''

Torpedo andersoni The Florida torpedo (''Torpedo andersoni'') is a rare and little-known species of electric ray in the family (biology), family Torpedinidae. It is known only from two specimens and a some wild sightings. Torpedoes have been recorded from three sc ...

'' Bullis, 1962 (Florida torpedo) * '' Torpedo bauchotae'' Cadenat, Capapé &

Desoutter The Desoutter Aircraft Company was a British aircraft manufacturer based in Croydon. It was founded by Marcel Desoutter and produced aircraft during the late 1920s and the 1930s. History The company was formed in December 1928 to manufacture t ...

, 1978 (Rosette torpedo) * ''

Torpedo fuscomaculata The black-spotted torpedo (''Torpedo fuscomaculata'') is a poorly known, uncommon species of electric ray in the family Torpedinidae, known for being capable of generating an electric shock. It is endemism, endemic to southern Africa and possibly ...

'' W. K. H. Peters, 1855 (Black-spotted torpedo) * '' Torpedo mackayana'' Metzelaar, 1919 (Ringed torpedo) * ''

Torpedo marmorata The marbled electric ray (''Torpedo marmorata'') is a species of electric ray in the family Torpedinidae found in the coastal waters of the eastern Atlantic Ocean from the North Sea to South Africa. This benthic fish inhabits rocky reefs, seagr ...

'' A. Risso, 1810 (Marbled electric ray) * '' Torpedo microdiscus'' Parin & Kotlyar, 1985 (Smalldisk torpedo) * ''

Torpedo panthera ''Torpedo panthera'' also known as the leopard torpedo is a species of fish in the family Torpedinidae. It is found in Djibouti, Egypt, Eritrea, India, Iran, Oman, Pakistan, Saudi Arabia, Somalia, Sudan, and Yemen. Its natural habitat ...

'' Olfers, 1831 (Leopard torpedo) * '' Torpedo semipelagica'' Parin & Kotlyar, 1985 (Semipelagic torpedo) * ''

Torpedo sinuspersici The Gulf torpedo (''Torpedo sinuspersici'') or variable electric ray, is a species of electric ray in the family Torpedinidae. It is found in the Indian Ocean, but may represent a species flock of several local endemic species. It is distinguis ...

'' Olfers, 1831 (Variable torpedo or Gulf torpedo) * '' Torpedo suessii'' Steindachner, 1898 * ''

Torpedo torpedo The common torpedo (''Torpedo torpedo''), also known as ocellate torpedo or eyed electric ray, is a species of electric ray in the family Torpedinidae. It is found in the Mediterranean Sea and the eastern Atlantic Ocean from the Bay of Biscay ...

'' (

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

, 1758) (Common torpedo) Two fossil species, '' T. acarinata'' Adnet, 2006 and '' T. pessanti'' Adnet, 2006, are known from the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

of southwestern

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

References

{{Authority control Ray genera Taxa named by Martinus Houttuyn