Torpedo (genus)

Torpedo
Temporal range: Early Eocene–Recent[1]
Common torpedo (T. torpedo)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Torpediniformes
Family: Torpedinidae
Bonaparte, 1838
Genus: Torpedo
Houttuyn, 1764
Type species
Raja torpedo
Linnaeus, 1758

Torpedo is a genus of rays, commonly known as electric rays, torpedo rays, or torpedoes. It is the sole genus of the family Torpedinidae. They are slow-moving bottom-dwellers capable of generating electricity as a defense and feeding mechanism. There are between fifteen and twenty-two extant species.[2][3]

The naval weapon known as the torpedo was named after this genus, whose own name is derived from the Latin word meaning "numb" or "paralysed"[4], presumably the sensation one would feel after experiencing the ray's electric shock.

Contents

Electricity

The largest species is the Atlantic torpedo, Torpedo nobiliana, which can grow to a weight of 90 kilograms (200 lb) and deliver a 220-volt electric shock. Electric rays have patches of modified muscle cells called electroplaques that make up an electric organ. These generate an electric gradient, similar to the normal electric potential across most cell membranes, but amplified greatly by its concentration into a very small area. The electricity can be stored in the tissues, which act as a battery. 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. Their tissue is often used in neurobiological research because of its unique properties.

Description

Torpedo rays are flat like other rays, disc-shaped, with caudal fins that vary in length. Their mouths and gill slits are located on their undersides. Males have claspers near the base of the tail. Females are ovoviviparous, meaning they form eggs but do not lay them. The young "hatch" within her body and she bears them live.[1]

Species

Family Torpedinidae Bonaparte, 1838

See also

References

  1. ^ a b Froese, Rainer, and Daniel Pauly, eds. (2009). "Torpedinidae" in FishBase. January 2009 version.
  2. ^ "Torpedo". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=564006. Retrieved October 12, 2008. 
  3. ^ Froese, Rainer, and Daniel Pauly, eds. (2011). Species of Torpedo in FishBase. February 2011 version.
  4. ^ Kidd, D.A. (1973). Collins Latin Gem Dictionary. London: Collins. ISBN 0-00-458641-7.