Torpedo (genus)

Spotted electric ray (Torpedo torpedo ), Underwater off the coast of Corsica.

The electric rays, Torpedo rays or electric ray (Torpedo (Latin: " torpere " be = slow) ) are a family within the order of the rays. They are also the only genus of the family Torpedinidae.

Electric rays have an electric organ ( electroplax ) of converted muscles, by means of which they can paralyze prey fish by electrical discharges 60-230 V and 30 amps. Compare diver the feeling of such underwater electric shocks with a very strong fist shock. This can possibly lead to unconsciousness.

Dissemination

Electric rays live near the coast and away from the coast in all temperate and tropical seas. They usually spend their time at depths of 1 to 250 m. Some species, such as the Atlantic torpedo (also known as Black electric ray, Torpedo nobilana called ) also occur at greater depths of up to 600 m.

Features

Electric rays are small to medium sized skates. Adult animals can depending on the type of between 15 cm (Torpedo bauchotae ) and 1.80 meters (Torpedo nobiliana ) are long. Head and body have grown into an oval or nearly round body disc. They are either exactly as wide as long or slightly broader than long. The body plate is naked and spineless.

The head is broad and flattened. The eyes on the top of the head are in front of the injection holes. They are small, but always well developed. The mouth is wide and curved. It is supported by two long cartilaginous plates, which have grown together with the cranium. It has no labial but clear mines at the mouth. The nostrils are located just before dam mouth at a distance, which is much smaller than the diameter of the nares. They are connected by wide Nasalgruben. The anterior nasal flaps are short, laterally expanded and fused together. They overlap the mouth. The teeth are small and unicuspid. You are not plate-like and stand 20 to 75 in a row. On the bottom are on each side five small gill openings just before the middle of the pectoral fin base. Reuse gill rays are missing.

The pectoral fins are large, ranging up to the snout and end only at the beginning of the pelvic fin base. There are the large, bean-shaped electric organs at the base of the pectoral fins. They can be seen through the skin. The pelvic fins are short and not divided into two praise. On the upper side of the body are located close together two dorsal fins, the first of which is always much larger. Both have the shape of a rounded triangle above. The first dorsal fin sits on the pelvic fin base behind the middle between the head and tail end. The strong, short tail clearly separates itself from the body, is haiähnlich and provided with a well-developed caudal fin. He is somewhat laterally flattened, has provided no spines on the top and is provided with lateral keels. The caudal fin is always much larger than the dorsal fins, about the size of the pelvic fins or greater. The spine bends in the tail upwards ( heterocercal ), a lower Schwanzflossenlobus missing. Torpedo rays swimming on the type of sharks with lateral impacts of the tail. The pectoral fins are not the type of genuine Rays in sine wave is still moving in the manner of de eagle rays at and struck off and are just as " wings " of meaning.

The color of the torpedo is uniform or marbled, mostly gray to brown or black. Light or dark punctures can occur in some species also ocelli.

Way of life

Electric rays are sluggish fish that spend buried in the sand or mud most of the time. They swim slowly and often rest on the sandy or muddy seabed. Only Torpedo nobiliana pelagic and takes long walks. They live on the upper regions of the continental slopes, the edges of the continental shelf, sandy coastal areas and muddy bays and estuaries, almost from the water surface to depths of 1100 meters. You do not tolerate brackish or fresh water. They feed on fish and invertebrates that are usually captured from the ground. Some species use their electric organs to stun bigger fish and then lead their prey with their long pectoral fins to the mouth. The mouth is highly extensible and allows them to swallow very large prey. Usually the electric organ is, however, used for defense against predators such as sharks. Some species are aggressive towards divers, others remain passive. Electric rays are ovoviviparous, the young hatch still in the mother's body or shortly after oviposition.

Species

The electric ray family includes 23 species. Probably the best known of the marble are torpedo (Torpedo marmorata ), the scalloped electric ray (Torpedo panthera ), and the spotted electric ray (Torpedo torpedo ), which is the most common species of electric ray. The largest member of the torpedo is the Atlantic torpedo (Torpedo nobiliana ), which reaches a length of up to 1.80 m.

• Torpedo adenensis Carvalho, Stehmann & Manilo, 2002.
• Torpedo alexandrinsis Mazhar, 1987.
• Torpedo andersoni Bullis, 1962.
• Torpedo bauchotae Cadenat, Capape & Desoutter, 1978.
• California electric ray (Torpedo californica ) Ayres, 1855.
• Torpedo fairchildi Hutton, 1872.
• Torpedo formosa Haas & Ebert, 2006.
• Black Polka Dot torpedo ray ( Torpedo fuscomaculata ) Peters, 1855.
• Torpedo mackayana Metzelaar, 1919.
• Torpedo macneilli ( Whitley, 1932).
• Marble electric ray (Torpedo marmorata ) Risso, 1810.
• Torpedo microdiscus Parin & Kotlyar, 1985.
• Atlantic electric ray (Torpedo nobiliana ) Bonaparte, 1835.
• Scalloped electric ray (Torpedo panthera ) Olfers, 1831st
• Torpedo peruana Chirichigno F., 1963.
• Torpedo puelcha Lahille, 1926.
• Torpedo semipelagica Parin & Kotlyar, 1985.
• Torpedo sinuspersici Olfers, 1831st
• Torpedo suessii Steindachner, 1898.
• Torpedo tokionis ( Tanaka, 1908).
• Spotted electric ray (Torpedo torpedo ) (Linnaeus, 1758).
• Torpedo tremens de Buen, 1959.

Etymology

Torpedo, the scientific name of the genus comes from the Latin. The meaning of " torpére " is " stunned his". Pliny called the familiar electric rays of the Mediterranean torpedo.

Cultural History

Plato can Menon of Pharsalus in his dialogue Meno, Socrates compare with an electric ray: Like this stun Socrates all who approach him. With stunning ushering is meant in aporia ( Menon 80a -c, 84b -c). Already in the year 76 AD to Pedanios Dioscorides have tried to treat over ' electric stimulation ' by the discharges of the fish epileptic seizures.