https://doi.org/10.1023/a:1013180330252. Wedekind, H., V. Hilge, and W. Steffens. Fish locomotion is powered by at most three (but mostly only two) morphologically differing myotomal muscle fibre types. Pages 523-641 in Report of the Bureau of Fisheries for 1904. North Carolina State Museum of Natural History, Raleigh, NC. Bryant A.J. Gillanders. S. F. Baird of the U.S. In most waters 10 pound fish could be considered small, and captures exceeding 20 pounds are not uncommon. The Russian Federation (0.06 Mt) followed by Poland (0.02 Mt), Czech Republic (0.02 Mt), Hungary (0.01 Mt) and Ukraine (0.01 Mt) represents about 70% of carp production in Europe during 2016. See Species Profile: Common Carp (Nonindigenous Aquatic species Database) for more information. In streams, the current will take the slack out of the line, thus the line must be kept tight. [citation needed], Common carp were brought to the United States in 1831. Knowledge and Management of Aquatic Ecosystems 420:28. https://doi.org/10.1051/kmae/2019017. Combatting the climate and nature emergency, How to identify swifts, swallows, sand martins and house martins. Optimum feeding rate and adaptation age for a commercial diet Optimum feeding rate and adaptation age for a commercial diet Author links open overlay panel P.L. Colorful varieties of Common Carp (i.e., nishikigoi or koi) are kept as pets in garden ponds and some have been introduced to ponds and public water bodies (Balon 1995). University Press of Mississippi. https://doi.org/10.1111/fme.12184. Freshwater Biology 50(3):403-417. https://doi.org/10.1111/j.1365-2427.2004.01330.x. 1996. Marine and Freshwater Research 72(11):1682. https://doi.org/10.1071/mf21051. Modeling control of Common Carp (Cyprinus carpio) in a shallow lake-wetland system. There is some question as to when and where Common Carp was first introduced into the United States. Accessed 24 September 2010. Mor, and N.B.D. About the oldest domesticates among fishes. You can cast to an area that appears to contain fish and you hope you're correct. [21] Although carp typically spawn in the spring, in response to rising water temperatures and rainfall, carp can spawn multiple times in a season. It is a major farmed species in European freshwater aquaculture with production localized in central and eastern European countries. Eder, S., and C.A. . Compensatory response of invasive common carp Cyprinus carpio to harvest. 2 (4th ed.). Lougheed, V.L., T. Thesmeer, T. Smith, and P. Chow-Fraser. Greater casting distance can also be achieved with longer rods (up to 10 to 11 feet in length). In commercial operations, spawning is often stimulated using a process called hypophysation, where lyophilized pituitary extract is injected into the fish. http://www.jstor.org/stable/43822857. Taylor, W.W., and C.P. North American Journal of Fisheries Management 14(2):442446. [25][26] After spreading massively through the MurrayDarling basin, aided by massive flooding in 1974,[25] they have established themselves in every Australian territory except for the Northern Territory. Rixon, C.A.M., I.C. Carp are members of the minnow family, with large golden scales. Launer. Distribution and natural history of the fresh and brackish water fishes of the Ochlocknee River, Florida and Georgia. The common carp is a heavy-bodied minnow with barbels on either side of the upper jaw. Once established in a water body, Common Carp is difficult and expensive to eliminate (e.g., Cahoon 1953). Matty The pond farming of carp is based on the ability of the species to accept and utilise cereals supplied by the farmers. Fish Commission 4(1884):266-267. Boston, C.M., R.G. 1996. Gibson-Reinemer, D.K., J.H. A Slovak Christmas Eve dinner is quite similar, with soup varying according to the region and fried carp as the main dish. Pinto, L., N. Chandrasena, J. Pera, P. Hawkins, D. Eccles, and R. Sim. Common carp ( Cyprinus carpio) has been in the United States for over 100 years. Yerger, and P.R. In Western Europe, the carp is cultivated more commonly as a sport fish, although there is a small market for it as a food fish. Science & Technical Publishing, New Zealand Department of Conservation, Wellington, New Zealand. The rain-soaked lands of Britain and Northern Ireland are rich in rivers, streams, lakes, ponds, canals and ditches. [13] Variants that have arisen with domestication include the mirror carp, with large, mirror-like scales (linear mirror scaleless except for a row of large scales that run along the lateral line; originating in Germany), the leather carp (virtually unscaled except near dorsal fin), and the fully scaled carp. Jenkins, R.E., and N.M. Burkhead. Brown, R.W., M. Ebener, and T. Gorenflo. 27 Oct. 2014. Aquaculture Research 11(1):1122. An 82-day study was conducted to assess the effect of the dietary lipid levels on growth performance, feed utilization, lipid deposition, and hepatopancreas lipometabolism of large-sized common carp (Cyprinus carpio). Hydrobiologia 632(1):235-245. https://doi.org/10.1007/s10750-009-9844-3. 2019. Fish farmers bred a population of common carp over many generations to have only a few patches of large scales on their bodies. Fishing for carp is normally done in two ways, the traditional angling methods using hook and line and with bow and arrow (bow-fishing). European carp,German carp, mirror carp, leather carp, Adults are light gold to dark brown in color, with reddish fins. Ross, S. 2001. . 1980. In Europe, common carp contributed 1.8% (0.17 Mt) of the total inland fisheries production (9.42 Mt) during 20152016. One of the most prominent features of the region's aquaculture is that it is based on the rearing of cyprinids, particularly the common carp. They are most abundant in large rivers, man-made lakes and natural lakes where there is abundant, soft organic matter on the bottom. Markle. Chemosphere 81(4):541-547. https://doi.org/10.1016/j.chemosphere.2010.06.033. Cole, L.J. A third subspecies, Cyprinus carpio haematopterus (Amur carp), native to eastern Asia, was recognized in the past,[4] but recent authorities treat it as a separate species under the name Cyprinus rubrofuscus. Journal of Great Lakes Research 36(1):100-112. https://doi.org/10.1016/j.jglr.2009.12.008. 2004. Enders, D. Watkinson, and D. Wrubleski. 307-354. Dann, S.L., and B.C. The wild common carp is Listed as Vulnerable on the global IUCN Red List of Threatened Species. FAO FishStat (2017) Fisheries and Aquaculture Software. Mayden. https://doi.org/10.1007/s10750-015-2356-4. https://doi.org/10.1016/j.biocon.2017.06.002. Regulated Invasive Species (MN DNR) are legal to buy, sell, transport, and possess, but may not be introduced into a free-living state, such as released into public waters. Carp are currently distributed in the lower Columbia (Arrow Lakes), lower Kootenay, Kettle (Christina Lake), and throughout the Okanagan system. FAO Fisheries and Aquaculture Department [online], Rome. Turbidity generation and biological impacts of an exotic fish Carassius auratus, introduced into shallow seasonally anoxic ponds. Origin and domestication of the wild carp, Cyprinus carpio: from Roman gourmets to the swimming flowers. Carp may spawn throughout the year in tropical areas of India, with peaks in January-March and July-August. Read our fundraising promise here. California Fish and Game. 1987. Downing. Commercial fishing for Carp. In the U.S., the Common Carp is more abundant in manmade impoundments, lakes, and turbid sluggish streams receiving sewage or agricultural runoff, and less abundant in clear waters or streams with a high gradient (Pflieger 1975; Trautman 1981; Ross 2001; Boschung and Mayden 2004; Ramirez-Herrejon et al. Smith, L.A. Thwaites, K.F. Grass carp do not have a suckerlike mouth as do common carp. As a result of subsequent population growth and dispersal, Common Carp spread even further. Fretueg, G.R., T.J. Martin, C. Widga, and D.R. The eggs hatch four to eight days later. Roy. 2017. Smiley, C.W. They also allow for a quick line pickup, which provides a more forceful hook set. University of Puget Sound Law Review 17:191-242. 1995. The common carp (Cyprinus carpio) is an extremely invasive species and an ecological destructive. Many veteran carp anglers also employ some type of bite indicator. Another small segment of species . Effects of natural environment and rearing conditions on the welfare and product quality of common. Plants that are commonly consumed include hydrilla, elodea, bladderwort, coontail, najas, milfoil, and potomegton spp. Ecological Applications 28(8):2066-2081. https://doi.org/10.1002/eap.1795. Socio-economic characterisation of specialised common carp (Cyprinus carpio L.) anglers in Germany, and implications for inland fisheries management and eutrophication control. Freshwater Fishes of Canada. thesis. New Zealand Journal of Marine and Freshwater Research 38:399-417. http://carpbusters.com/documents/Sorensen_Stacey[1].2004.NZJfinal.pdf. Goldsborough. They can eat a herbivorous diet of aquatic plants, but prefer to scavenge the bottom for insects, crustaceans (including zooplankton), crawfish, and benthic worms. Canadian Journal of Fisheries and Aquatic Science 60:182-192. 2016. Bow-fishing can provide a great deal of challenge, action, and excitement. Ecological impacts of an exotic benthivorous fish in large experimental wetlands, Delta Marsh, Canada. It has large pectoral fins and a tapering dorsal fin running down the last two thirds of its body, getting progressively higher as it nears the carp's head. Ivanekha, and V.V. Bowlby. (2009) performed ecological niche modeling to examine the invasion potential for Common Carp and three other invasive cyprinids (Grass Carp, Nico, L., E. Maynard, P.J. Liepnieks, K. Kenelty, S.M. It usually spawns in spring, when the female deposits numerous eggs on plants or detritus, usually in shallow water. Common carp was more sensitive to cadmium toxicity. Catchability and stock density of Common Carp, Cyprinus carpio L. in a lake fishery. Rahel, F.J., and R.L. Treble hooks in sizes 8-12 work best and can be used with a variety of baits. Inland Fishes of California. Sorensen, PW and NE Stacey. They were first noted in the Okanagan Valley in 1912, as was their rapid growth in population. Journal of Freshwater Ecology 33(1):83-96. https://doi.org/10.1080/02705060.2018.1423645. About 96 per cent of common carp accumulate on Australia's east coast. Common carp (Cyprinus carpio) are fish that have small, evenly-spaced scales covering their entire bodies. Sorensen. Its caudal and anal fins may either be a dark bronze or washed with a rubbery orange hue. Hartel et al. Crane. They can typically be found in small schools, although larger carp often lead a solitary existence. Page, L.M., and B.M. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. Carlson. Does not possess a true spine. Schroeder. The daily growth of carp can be 2 to 4 per cent of body weigh. McLaughlin. TheWildlife Trusts is a movement made up of 46 Wildlife Trusts: independent charities with a shared mission. 2009. 1975. [2][3] The native wild populations are considered vulnerable to extinction by the International Union for Conservation of Nature (IUCN),[1] but the species has also been domesticated and introduced (see aquaculture) into environments worldwide, and is often considered a destructive invasive species,[2] being included in the list of the world's 100 worst invasive species. 1987. Although carp eradication measures have been active for over 100 years, long-established species, like the common carp, are present in almost every state. As carp biomass goes up, vegetation goes down and lakes become turbid. Biocontrol of the Common Carp (Cyprinus carpio) in Australia: A Review and Future Directions. For problems and technical issues, contact Matthew Neilson. So do not get anything too fancy. One catching sewage or farm runoff is especially nice. Keywords: Common carp; Swimming exercise; Metabolic adaptation; Serum compounds Introduction The number of fish species exceeds 32400 [1] and most of them swim by undulations of the whole body [2]. Fishing arrows work the best because the weight gives the best penetration. [20], An egg-layer, a typical adult female can lay 300,000 eggs in a single spawn. Managing a migratory pest species: A selective trap for Common Carp. Bonneau, J.L., and D.L. Character of the carp introduced by Capt. Henry Robinson about 1830. In another case, Miller and Beckman (1996) documented white sturgeon Acipenser transmontanus eggs in the stomachs of Common Carp in the Columbia River. Biological Conservation 212:7485. Additionally, common carp usually fight harder than mirror carp do when they have been hooked. It gives its name to the carp family, Cyprinidae. Updated 12 July 2005. Sorenson. (1996) noted that more than 20,000 Common Carp were killed by a bacterial disease over a short period of time in the Merrimack River in the late 1970s. Williams, and M.St.J. [citation needed][19] Common carp feed throughout the day with the most intensive feeding at night and around sunrise. [30][31], Efforts to eradicate a small colony from Lake Crescent in Tasmania, without using chemicals, have been successful, but the long-term, expensive and intensive undertaking is an example of both the possibility and difficulty of safely removing the species once it is established. Canadian Journal of Fisheries and Aquatic Sciences 38(12):1539-1561. https://doi.org/10.1139/f81-206. 2014. We highly recommend reviewing metadata files prior to interpreting these data. insight of adaptation to temperatures, calculation of chromosomes and investigation for thaw of frozen cells. Schofield, M. Cannister, J. Larson, A. Fusaro, M. Neilson, and A. Bartos, 2023. One of the most important adaptations to Bighead carp is the fact that these fish can grow to large sizes so quickly. Journal of Fish Diseases 40(9):11411153. Natural History of New York. McNyset, J.B. Williams, A.T. Peterson, and E.O. Fish Commission for the season of 1885-'86. 624 pp. In Carp Fishing Science", "Aanvullend Archeologisch Onderzoek op terrein 9 te Houten-Loerik, gemeente Houten (U. Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted. Aquatic invasive species. Native to Asia, and spread throughout Europe by the Romans . https://doi.org/10.1111/jfd.12591. As aquaculture became a profitable branch of agriculture, efforts were made to farm the animals, and the culture systems soon included spawning and growing ponds. Common carp can grow to very large sizes if given adequate space and nutrients. Marking. Fadhil, A.B., E.T.B. Badiou, P.H.J., and L.G. Line strength depends upon water conditions, potential obstacles, size of fish, and angler expectations. Journal of Fish Biology, 65 (Supplement A): 127. Common carp (Cyprinus carpio), sport fishes, and water quality: ecological thresholds in agriculturally eutrophic lakes. [citation needed], Both European and Asian subspecies have been domesticated. An important adaptation of the skin mucosa to the aquatic environment is the microbiota inhabiting the mucus. 2018. 4857. Common carp have a very fast growth rate and can reach a length of 16 inches within the first four years of their growth. Carp are notorious bottom feeders that uproot aquatic vegetation. Pflieger, W.L. The reel should have a good drag system as well as having the capacity to hold at least 75 yards of 20 lb. The annual tonnage of common carp produced in China alone, not to mention the other cyprinids, exceeds the weight of all other fish, such as trout and salmon, produced by aquaculture worldwide. Southern naiad is a rooted native aquatic plant that grows from the bottom of the pond. [36] In the late 19th century, they were distributed widely throughout the country by the government as a food-fish, but they are now rarely eaten in the United States, where they are generally considered pests. and Mraz, J. McDonald, M. 1886. Proceedings of the Southeastern Association of Game and Fish Commissions 24: 352-377. The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. Buchanan. Stuart, I.G., A. Williams, J. McKenzie, and T. Holt. [12] The common carp's native range also extends to the Black Sea, Caspian Sea, and Aral Sea. Overview of potential piscicides and molluscicides for controlling aquatic pest species in New Zealand. Bureau of Rural Sciences (Department of Agriculture, Fisheries and Forestry Australia), Canberra. Common carp (Cyprinus carpio Linnaeus, 1758) is one of the most widespread fish species in the temperate regions of the world . Swift, C., R.W. Taylor, J., R. Mahon. [7][8], The common carp is native to Europe and Asia and has been introduced to every part of the world except the poles. Freshwater fishes in the U.S.S.R. and neighboring countries, Vol. Aquatic plant numbers can decline because of reduced water . 1994. 1991. For these reasons, the species was denigrated as a "trash fish" by . 1976. Effects of adult common carp (Cyprinus carpio) on multiple trophic levels in shallow mesocosms. 2005. McColl, K.A., and A. Sunarto. Moyle, P.B. Sorensen. 5. 2018). It had two pairs of barbels and a mesh-like scale pattern. https://doi.org/10.1007/s10530-012-0203-3. Preferred Habitat Grass Carp prefer large, slow flowing water bodies and spawn in large rivers with moderate currents. Sauver. 1981. https://doi.org/10.1007/s10530-017-1655-2. The bighead carp is a large, heavy-bodied fish with an exceptionally large head, upturned mouth, small scales, and scattered, irregular dark blotches over the entire body. The size and style of hook used for carp fishing influences the number and size of fish caught. 536 pp. "Domestic" carp grow a lot larger than native carp and are much larger with deeper bodies. 1999. Missouri Department of Conservation. This, in turn, will give the declining population of the native June sucker a chance to recover. Pearson, J., J. Dunham, J.R. Bellmore, and D. Lyons. Carefully approach the carp by boat or wading. Berg, L.S. AIS )", "Kennisdocument Karper Sportvisserij Nederland", Cultured Aquatic Species Information Programme , "Diel pattern in common carp landings from angling competitions corresponds to their assumed foraging activity", "Carp Fishing for carp fishing information", "Bigmouth Buffalo Ictiobus cyprinellus sets freshwater teleost record as improved age analysis reveals centenarian longevity", "Carp in Australian rivers | NSW Department of Primary Industries", "Mother of all Aussie carp may be German", Victorian Recreational Fishing Guide 2006-2007, Carp finally find fans as fertiliser demand skyrockets for veggie gardens during pandemic, "Carp success, after long battle against invasive fish, has trout faithful rejoicing", "Herpes virus to be used in fight against carp in Murray River, Christopher Pyne says", "Genetic variation in resistance and high fecundity impede viral biocontrol of invasive fish", "USGS Nonindigenous Aquatic Species Program", "Utah Lake carp census gauges whether evictions-by-the-ton are succeeding", "Experiment shows it is possible for fish to migrate via ingestion by birds", "Experimental evidence of dispersal of invasive cyprinid eggs inside migratory waterfowl", "Nutrient footprint and ecosystem services of carp production in European fishponds in contrast to EU crop and livestock sectors", Carp herpesvirus - Managing Water Ecosystems - CSIRO, https://en.wikipedia.org/w/index.php?title=Eurasian_carp&oldid=1142910577, Articles with dead external links from November 2019, Articles with permanently dead external links, Articles with unsourced statements from April 2021, Articles with unsourced statements from January 2020, Articles with unsourced statements from November 2020, Articles needing additional references from April 2021, All articles needing additional references, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 5 March 2023, at 00:09. More recently introductions of Common Carp have resulted because of the use of juvenile carp as bait fish (e.g., Swift et al. Commercial carp removal at Lake Mattamuskeet, North Carolina. In general, carp may be found any place in a river where you would expect to catch fish. Maceda-Veiga, A., R. Lopez, and A.J. Scott, W.B., and E.J. Green. Contents 1 Biology 2 Species 3 Recreational fishing 4 Aquaculture 5 Breeding 6 As ornamental fish 7 As food 8 List of carp-based dishes This method has been shown to reduce their impact within 24 hours and greatly increase native vegetation and desirable fish species. They said the toxicity Carp (Cyprinus Carpio).. Three strains of European Carp have been introduced to Australia, an ornamental strain near Sydney (1850-60), a Singaporean strain in the Murrumbidgee (1876), and a hybrid "Boolara" strain in Victoria . Spawning on nests, aquatic weeds and inundated grass in tanks and ponds. Aliens Among Us. Michigan State University Press, East Lansing, MI, pp. The average productivity of carp culture systems in central European countries ranges between 0.3 and 1 ton ha1. Duggan, N.M.N. Inland Fishes of California. Journal of Wildlife Management 31(1):181-188. https://doi.org/10.2307/3798375. Tang, L. Matos, and M. Neff. . Pandey and Madhuri [25] Studied on the heavy metal causing toxicity in animal and fishes; for this purpose they studied the such as Hg, Pb, Cu and Cd concentrations in the environment, fish and other animals. A variety of baits can be used to fish for carp, but the most common are doughballs, corn, and worms. Fisheries Research 61:1933. [4] In Europe, domestication of carp as food fish was spread by monks between the 13th and 16th centuries. The European common carp production, in terms of volume, reached its peak (0.18 Mt) during 20092010 and has been declining since. It frequents ponds, gravel pits and lakes, but is not native to the UK, being introduced in the Middle Ages. Clear, running water: no thanks. One of the most important adaptations to Bighead carp is the fact that these fish can grow to large sizes so quickly. Summerfelt, R.C., P.E. Several agents of the U.S. Common carp is a regulated invasive species. Aquatic Ecosystem Health & Management 21(3):318-330. https://doi.org/10.1080/14634988.2018.1498272. Hocutt, R.E. Study with Quizlet and memorize flashcards containing terms like Why are catfish and carp found at the mouth of a river, while trout are found nearer the source?, Explain how a streamlined, smooth, nearly hairless body is a beneficial adaptation for marine animals., Freshwater biomes have _____. [32] One proposal, regarded as environmentally questionable, is to control common carp numbers by deliberately exposing them to the carp-specific koi herpes virus with its high mortality rate. Bajer, P.G., G. Sullivan, and P.W. Genetic divergence between. 1967. The Eurasian carp or European carp (Cyprinus carpio), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia. Waltzek. Breeding is carried out in hapas, cement tanks or small ponds. The oldest Common carp on record was 38 years old, with the average lifespan of this fish reaching 20 years of age. https://doi.org/10.1016/s0165-7836(02)00243-6. The Romans farmed carp and this pond culture continued through the monasteries of Europe and to this day. Retriever reels are preferred because you can put very heavy line on them (200-400 lbs.). The American Midland Naturalist 173(3):294304. Fly rods in the 7- to 9-weight range are preferred because it has the extra backbone to turn these fish. Waltzek, and E. Soto. Fayetteville, AR. 2003. https://doi.org/10.3354/dao03296. 2, pp. Lake and Reservoir Management 26(1):12-22. https://doi.org/10.1080/07438140903500586. Carp which survive to juvenile are preyed upon by other fish such as the northern pike and largemouth bass, and several birds (including cormorants, herons, goosanders, and ospreys)[22] and mammals (including otter and mink). 1977). . They naturally live in temperate climates in fresh or slightly brackish water with a pH of 6.59.0 and salinity up to about 0.5%,[17] and temperatures of 3to 35C (3795F). The best chance of catching a carp on the fly would be from choosing a fly that imitates a food that the carp recognizes. Ecological impacts of an exotic benthivorous fish, the common carp (Cyprinus carpio L.), on water quality, sedimentation, and submerged macrophyte biomass in wetland mesocosms. McCarraher, D.B., and R.W. 2021. Hydrobiologia 755(1):107121. Avoid transporting young and adult carp between lakes while fishing, or during other recreational activities. [38] Another method of control is to trap them with seine nets in tributaries they use to spawn, and exposing them to the piscicide rotenone. 82(2): 66-80. 2006. Lucchesi, and T.R.St. The average size of the common carp is around 4080cm (1631 inches) and 214kg (4.430.9lb). http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005451. The techniques used are similar to those used for fishing for bonefish and on occasion, carp will take a fly from the surface. Linfield, R.S.J. [1][5], The carp has a robust build, with a dark gold sheen most prominent on its head. The tanks were . University of Wisconsin, La Crosse, WI. Bhavsar, S.P., K.G. Goldsborough. Updated 14 September 2017. Often the fish were released from railroad tank cars at bridge crossing directly into streams (e.g., McDonald 1886). This adaptation allows Bighead carp to overrun many of the native fish as they eat the main food supply. The common carp is one of the largest members of the minnow family and a close relative of the goldfish. American Fisheries Society, Bethesda, MD. The best style of hook is a size 6 or 8 shortshanked with straight eye. 2004. Nonindigenous Aquatic Species Database. Sight casting has its origins from the flats of the tropics. 2019. (Cited as a work rather than as individual accounts in the interest of space). Journal of Zoological Systematics and Evolutionary Research 42(4): 266269. Page. With the sand and light gravel bottoms most of the food sources will be various source of crustaceans, insect nymphs, and aquatic worms or vegetation debris. Invasion risks posed by the aquarium trade and live fish markets on the Laurentian Great Lakes. Brown, D.O. . 2018. Widespread and enduring demographic collapse of invasive common carp (Cyprinus carpio) in the Upper Mississippi River System. 1994. Reels come in all shapes and sizes. Journal of Great Lakes Research 30(1):44-57. https://doi.org/10.1016/S0380-1330(04)70328-7. Drouillard, R.W.K. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables. They range from simply draping a piece of paper over the line to elaborate electrical devices.