Torpedo Torpedo

[Giulia Satmary]

Thecommon 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 to Angola, and is a benthic fish typically encountered over soft substrates in fairly shallow, coastal waters. Growing to 60 cm (24 in) long, this species has a nearly circular pectoral fin disc and a short, thick tail with two dorsal fins of nearly equal size and a large caudal fin. It can be identified by the prominent blue spots on its back, which usually number five but may vary from zero to nine, as well as by the small knobs on the rims of its spiracles.

The common torpedo and other electric rays were familiar to the peoples of classical antiquity. Torpedo was the Roman name for electric rays, derived from Latin torpere meaning 'to be numb'.[2][3] Carl Linnaeus, known as the "father of taxonomy", scientifically described the common torpedo as Raja torpedo in the 1758 tenth edition of his Systema Naturae. However, the common torpedo also appeared in at least 52 pre-Linnaean sources under various names such as Torpedo, Raja tota lvis, Torpedo maculosa, and Torpedo Sins Persici. These early accounts, including Linnaeus's, confounded the common torpedo with other electric ray species. As Linnaeus did not indicate any type specimens, the designation of a lectotype or neotype is warranted in the interest of taxonomic stability. This measure has yet to be taken.[4]

Peter Forsskl validly published the genus name Torpedo in 1775, predating the use of the genus name Torpedo by Dumril in 1806, meaning that Torpedo Dumril, 1806 (often cited in catalogs) is a junior homonym of Forsskl's name and cannot be used.[5] Forsskl included only a single species, Raja torpedo Linnaeus, 1758, thereby making it the type species of the genus. While Forsskl's description indicated that he had misinterpreted Linnaeus' name and ascribed it to another electric fish (currently known as Malapterurus electricus), this potential source of confusion was rectified in 2008, when Raja torpedo Linnaeus was officially made the type species under ICZN Article 70.3.1.[5] Within the genus Torpedo, the common torpedo is placed within the subgenus Torpedo, which differs from the other subgenus Tetronarce in having spiracles with papillate rims and ornate dorsal coloration.[6] This species may also be referred colloquially to as crampfish, cramp ray, or torpedo ray.[7][8]

Solitary and nocturnal, the common torpedo spends much time resting on the sea floor, often buried in sediment.[11] It is an ambush predator that pounces onto prey and stuns them with electricity, the process taking only a fraction of a second. Once the prey is immobilized, it is manipulated to the mouth with motions of the disc, and swallowed whole.[17] Adults feed almost entirely on small benthic bony fishes, including soles, herring, mullet, gobies, goatfishes, porgies, dragonets, and jack mackerels. Large decapod crustaceans are a minor secondary food source, while very rarely skates may be consumed. Juveniles are less exclusively piscivorous than the adults and feed on a variety of invertebrates as well. The most significant prey species differ between seasons and geographic regions. For example, in the Tyrrhenian Sea, juvenile common sole (Solea solea) are by far the most important prey item in autumn and winter, but in spring and summer they become less available and other fishes figure more prominently in the ray's diet.[19][20] Known parasites of this species include the tapeworm Phyllobothrium lactuca,[21] and the monogeneans Amphibdella paronaperugiae[22] and Amphibdelloides benhassinae.[23]

Sexual segregation occurs during the breeding season as pregnant females move into shallow coastal waters. The common torpedo is unusual among sharks and rays in that birthing has been documented both at higher and at lower salinities than seawater, in estuaries and lagoons.[15] Immediately after birth, this species is capable of producing electric shocks of up to four volts. Newborns grow rapidly, with a commensurate increase in electrogenic capacity: after four months, they almost double in weight and can generate 26 volts.[17] Males and females mature sexually at similar lengths: 25 and 26 cm (9.8 and 10.2 in) respectively in the Tyrrhenian Sea,[25] 18 and 22 cm (7.1 and 8.7 in) respectively off Egypt,[19] 19 cm (7.5 in) for both off Tunisia, and 30 and 31 cm (12 and 12 in) respectively off Senegal.[15]

The electric shock of the common torpedo can be severe, but is not life-threatening.[26] In classical antiquity, the electrogenic properties of this species led it (and other strongly electric fishes) to be used in medicine for the treatment of pain and diseases such as gout.[27] For example, the Roman physician Scribonius Largus, in his Compositiones medicae (c. 50 AD), recommended that chronic headaches be treated by the application of a live torpedo to the affected area.[28] The common torpedo is edible, but is little-valued by commercial or artisanal fisheries and is mostly discarded when caught. Because of its shallow-water habits, it may survive being captured and discarded relatively well. It is susceptible to several types of demersal fishing gear, including bottom trawls and trammel nets; fishing activity is heavy within its range but no specific data regarding this species are available. The International Union for Conservation of Nature (IUCN) has listed it as Vulnerable.[1] The common torpedo has been kept in aquariums, but requires live fish for food.[8]

This small torpedo has an oval pectoral disc with a straight edge at the very front, an elongated body with rounded pelvic fins, and two small dorsal fins set back on its stout tail near its triangular caudal (tail) fin. It is white underneath, and reddish brown on top, with five dark blue spots ringed with dark and light accents.

The solitary nocturnal fish scavenges the shallow coastal sea floor for crustaceans and bony fish, using the kidney-shaped electric organs on either side of its head to stun its prey. Although it can only shock a human, because of its shallow habitat, caution should be used when possibly interacting with this torpedo.

Although the common torpedo is edible, it is typically discarded when taken as bycatch in commercial and artisanal fisheries. Due to its shallow water habitats, the common torpedo often survives being captured and discarded. It is susceptible to demersal fishing gear such as bottom trawls and trammel nets and although fishing pressure is intense within its geographic range, there is no specific data on this species. This species can be maintained in aquariums, however it requires a supply of live fish for food.

This demersal species prefers soft bottoms including sandy flats and seagrass beds, typically in inshore locations although it is occasionally observed in deeper waters. It is most commonly observed in tropical waters to 1,312 feet (400 m) in depth within its geographical range.

Distinctive Features

The disc of the common torpedo is circular in shape with a nearly straight front edge. The eyes and spiracles are small with the lateral and posterior rims of the spiracles possessing low knobs which tend to decrease in size as the individual ages.

Behind the spiracles, on the nape is a pair of mucous pores and on either side of the head are two large, kidney-shaped electric organs that are visible just beneath the skin. A wide, quadrangular flap of skin is located between the nostrils, almost reaching the mouth.

Five pairs of gill slits are located on the ventral side of the disc. The distinct pelvic fins have rounded outer margins and the short thick tail possesses skin folds along both sides with two dorsal fins located on the top, the first of which is slightly larger than the second. The caudal fin is triangular in shape with rounded corners and is roughly as long as the space between it and the first dorsal fin. The smooth skin lacks dermal denticles.

Coloration

The common torpedo has a disc-shaped body that is light to dark brown in color on the dorsal surface. Within this area are distinct large spots, also known as ocellae. Each spot is blue and circled by darker and lighter rings. Usually there are five ocellae in a symmetrical row of three and another row of two. Torpedos with less ocellae are uncommon and those with more than five are quite rare although not unknown. An individual was caught off of Tunisia with eight ocellae and another with nine off of southern France.

Dentition

The small teeth are arranged within the jaws in a dense quincunx patter, with 22-24 tooth rows in the upper jaw and 20-22 tooth rows in the lower jaw. Each tooth has a single sharp cusp.

Food Habits

Adult common torpedos feed primarily on benthic bony fish such as soles, herring, gobies, mullet, goatfish, porgies, dragonets, and jack mackerels. In addition, they are also known to occasionally eat crustaceans and even skates. In contrast, juveniles feed on a variety of marine invertebrates.

Up to 19 young are born per litter, measuring 3.1-3.8 inches (8.0-9.7 cm) long. In the waters off West Africa, gestation lasts 6-8 months with birth occurring from September through October. Litter sizes can number up to 28 young with the newborns measuring 4.0-4.9 inches (10.2-12.5 cm) in length. Litter size increases correspondingly with the size of the female.

The newest way to activate #torpedospeed is here. Finally, a computer mount that perfectly positions data no matter what type of bottle you like to use. Raise the computer mount up to tuck in a Refill Bottle for race day, or lower it down to clear a Standard Bottle to maintain the optimal view for training days.

The first successful torpedo program by the U.S. Navy began in 1870. Lieutenant Commander John A. Howell created a torpedo that was driven by a 132-pound flywheel that spun to 10,000 revolutions per minute. A steam turbine housed on the torpedo tube spun the flywheel before it launched. The Navy produced about 50 of the Howell torpedoes for tactical use. Eventually, the U.S. would go to the Whitehead and Bliss-Leavitt torpedoes that would make up the U.S. arsenal until 1910. The Whitehead Mk 5 could go about 4,000 yards at speeds up to 27 knots.

3a8082e126