silver carp

The silver carp is a filter feeder, and possesses a specialized feeding apparatus capable of filtering particles as small as 4 μm. The gill rakers are fused into a sponge-like filter, and an epibranchial organ secretes mucus, which assists in trapping small particles. A strong buccal pump forces water through this filter. Silver carp, like all Hypophthalmichthys species, have no stomachs; they are thought to feed more or less constantly, largely on phytoplankton, and also consume zooplankton and detritus. In places where this plankton-feeding species has been introduced, they are thought to compete with native planktivorous fishes, which in North America include paddlefish (Polyodon spathula), bigmouth buffalo (Ictiobus cyprinellus), gizzard shad (Dorosoma cepedianum), and young fish of almost all species.{{cite journal|last=Willink|first=P. W.|year=2009|title=Bigheaded Carps: A Biological Synopsis and Environmental Risk Assessment|journal=Copeia|volume=2009|issue=2|pages=419–421|doi=10.1643/ot-09-041|s2cid=85598132}}{{Cite journal |last1=Minder |first1=Mario |last2=Pyron |first2=Mark |date=2017-05-30 |title=Dietary overlap and selectivity among silver carp and two native filter feeders in the Wabash River |url=http://dx.doi.org/10.1111/eff.12365 |journal=Ecology of Freshwater Fish |volume=27 |issue=1 |pages=506–512 |doi=10.1111/eff.12365 |issn=0906-6691|url-access=subscription }}

Because they feed on plankton, they are sometimes successfully used for controlling water quality, especially in the control of noxious blue-green algae (cyanobacteria). Certain species of blue-green algae, notably the often toxic Microcystis, can pass through the gut of silver carp unharmed, picking up nutrients in the process. Thus, in some cases, blue-green algae blooms have been exacerbated by silver carp, and Microcystis has also been shown to produce more toxins in the presence of silver carp. These carp, which have natural defenses to their toxins, sometimes can contain enough algal toxins in their systems to become hazardous to eat.

The silver carp in its natural range migrate upstreams for spawning; eggs and larvae then drift downstream, and young fish hatch in the floodplain zone. Larvae and small juveniles feed on zooplankton, switching to phytoplankton once a certain size is reached. The species is somewhat sensitive to low oxygen conditions.{{cite book |last1=Frimodt |first1=Claus |title=Multilingual illustratet guide to the worlds commercial coldwater fish |date=1995 |publisher=Fishing New Books |location=Farnham, Surrey |isbn=9780852382134 |page=215 |edition=1 |url=https://www.fishbase.se/references/FBRefSummary.php?ID=9987 |access-date=23 November 2023}}

The species is currently classified as near threatened in its original range, as its habitat and reproductive behavior are impacted by construction of dams, pollution, and overfishing. Population declines appear to have been particularly significant in the Chinese parts of its range.

{{Main|Carp fishing}}

Silver carp are filter feeders, thus are difficult to catch on typical hook-and-line gear. Special methods have been developed for these fish, the most important being the "suspension method", usually consisting of a large dough ball that disintegrates slowly, surrounded by a nest of tiny hooks embedded in the bait. The entire apparatus is suspended below a large bobber. The fish feed on the small particles released from the dough ball and bump against the dough ball, with the intention of breaking off more small particles that can be filtered from the water, eventually becoming hooked on the tiny hooks.{{citation needed|date=October 2015}}

In some areas, using "snagging gear", in which large weighted treble hooks are jerked through the water, is legal to snag the fish. In the United States, silver carp are also popular targets for bowfishing; they are shot both in the water and in the air. In the latter case, powerboats are used to scare the fish and entice them to jump out of the water, and the fish are shot when they are airborne.{{citation needed|date=October 2014}}

Two other species are in the genus Hypophthalmichthys, the bighead carp (H. nobilis) and the largescale silver carp (H. harmandi). The genus name Aristichthys has also sometimes been used for bighead carp, but is deprecated.[http://www.fws.gov/contaminants/OtherDocuments/ACBSRAFinalReport2005.pdf ACBSRA Final Report 2005] {{webarchive |url=https://web.archive.org/web/20070203012418/http://www.fws.gov/contaminants/OtherDocuments/ACBSRAFinalReport2005.pdf |date=February 3, 2007 }} The bighead carp differs from the silver carp in its behavior (it does not leap from the water when startled) and also in its diet. Bighead carp are also filter feeders, but they filter larger particles than silver carp, and in general consume a greater proportion of zooplankton in their diets than silver carp, which consume more phytoplankton.{{cite journal |last1=Fu |first1=Cuizhang |last2=Wu |first2=Jihua |last3=Wang |first3=Xinyi |last4=Lei |first4=Guangchun |last5=Chen |first5=Jiakuan |title=Patterns of diversity, altitudinal range and body size among freshwater fishes in the Yangtze River basin, China |journal=Global Ecology and Biogeography |date=November 2004 |volume=13 |issue=6 |pages=543–552 |doi=10.1111/j.1466-822X.2004.00122.x |bibcode=2004GloEB..13..543F |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1466-822X.2004.00122.x |access-date=23 November 2023 |language=en |issn=1466-822X|url-access=subscription }} In at least some parts of the United States, bighead and silver carp hybridize in the wild and produce fertile offspring.{{cite book |last1=Etnier |first1=David |last2=Starnes |first2=Wayne |title=The Fishes of Tennessee |date=1 January 1993 |publisher=University of Tennessee Press |location=Knoxville |isbn=0-87049-711-1 |page=74 |url=https://trace.tennessee.edu/utk_utpress/2/ |access-date=23 November 2023}}

The largescale silver carp is closely related to the silver carp, but its native range is to the south of that of the silver carp, mostly within Vietnam.{{cite journal |last1=Xian |first1=Qiming |last2=Ramu |first2=Karri |last3=Isobe |first3=Tomohiko |last4=Sudaryanto |first4=Agus |last5=Liu |first5=Xiaohua |last6=Gao |first6=Zishen |last7=Takahashi |first7=Shin |last8=Yu |first8=Hongxia |last9=Tanabe |first9=Shinsuke |title=Levels and body distribution of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in freshwater fishes from the Yangtze River, China |journal=Chemosphere |date=1 March 2008 |volume=71 |issue=2 |pages=268–276 |doi=10.1016/j.chemosphere.2007.09.032 |pmid=17980898 |bibcode=2008Chmsp..71..268X |url=https://www.sciencedirect.com/science/article/abs/pii/S0045653507011861 |access-date=23 November 2023 |issn=0045-6535|url-access=subscription }} Unlike bighead and silver carp, largescale silver carp have not been widely introduced around the world for use in aquaculture, although at least one introduction was made to some waters of the Soviet Union, where they hybridized with the introduced silver carp.{{cite journal |last1=Li |first1=Shan |last2=Wei |first2=Hui |last3=Vilizzi |first3=Lorenzo |last4=Zhan |first4=Aibin |last5=Olden |first5=Julian D. |last6=Preston |first6=Daniel L. |last7=Clarke |first7=Stacey A. |last8=Cudmore |first8=Becky |last9=Davies |first9=Gareth D. |last10=Wang |first10=Xiaoming |last11=Copp |first11=Gordon H. |title=The Future of Legislation, Policy, Risk Analysis, and Management of Non-Native Freshwater Fishes in China |journal=Reviews in Fisheries Science & Aquaculture |date=3 April 2021 |volume=29 |issue=2 |pages=149–166 |doi=10.1080/23308249.2020.1782830 |bibcode=2021RvFSA..29..149L |url=https://www.tandfonline.com/doi/abs/10.1080/23308249.2020.1782830 |access-date=23 November 2023 |language=en |issn=2330-8249|url-access=subscription }}

{{main|Asian carp in North America}}

Silver carp were imported to North America in the 1970s to control algal growth in aquaculture and municipal wastewater treatment facilities, but escaped from captivity soon after their importation,{{cite web|url=https://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=549|title=USGS NAS silver carp fact sheet|access-date=2017-09-11|archive-date=2009-05-10|archive-url=https://web.archive.org/web/20090510112413/http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=549|url-status=dead}} and are now considered a highly invasive species.{{cite web|last1=Conover|first1=G.|last2=Simmonds|first2=R.|last3=Whalen|first3=M.|year=2007|title=Management and control plan for bighead, black, grass, and silver carps in the United States|publisher=Aquatic Nuisance Species Task Force, Asian Carp Working Group|location=Washington, DC|url=http://www.asiancarp.org/Documents/Carps_Management_Plan.pdf|url-status=dead|archive-url=https://web.archive.org/web/20170213222134/http://www.asiancarp.org/documents/Carps_Management_Plan.pdf|archive-date=2017-02-13}}

Silver carp, with the closely related bighead carp, often reach extremely high population densities, and are known to have undesirable effects on the local environments and native species, including the bigmouth buffalo.{{Cite journal|last1=Lackmann|first1=Alec R.|last2=Andrews|first2=Allen H.|last3=Butler|first3=Malcolm G.|last4=Bielak-Lackmann|first4=Ewelina S.|last5=Clark|first5=Mark E.|date=2019-05-23|title=Bigmouth Buffalo Ictiobus cyprinellus sets freshwater teleost record as improved age analysis reveals centenarian longevity|journal=Communications Biology|language=En|volume=2|issue=1|page=197|doi=10.1038/s42003-019-0452-0|pmid=31149641|pmc=6533251|issn=2399-3642|doi-access=free}} They have spread into the Mississippi, Illinois, Ohio, Missouri, Tennessee, Wabash Rivers, and many of their tributaries in the United States, and are abundant in the Mississippi catchment from Louisiana to South Dakota and Illinois. Dams seem to have slowed their advance up the Mississippi River, and until late November 2008, silver carp had not been captured north of central Iowa on the Mississippi.{{cite news|url=http://www.jsonline.com/news/wisconsin/35410349.html|title=Jumping silver carp discovered in Wisconsin waters|author=Dan Egan|newspaper=Journal Sentinel|date= 2 December 2008}} Dams that do not have navigation locks are complete barriers to natural upstream movement of silver carp, unless fishermen unintentionally assist this movement by the use of silver carp as bait.

In 2020, Alabama Department of Conservation and Natural Resources found silver carp in Alabama's Pickwick and Wheeler reservoirs on the Tennessee River, but the species has not expanded its range in Alabama’s waterways.{{cite news |last1=Rainer |first1=David |title=WFF Cautiously Optimistic About Spread of Silver Carp |url=https://content.govdelivery.com/accounts/ALDNR/bulletins/29eb8cc |access-date=4 September 2020 |work=Outdoor Alabama Weekly |agency=Alabama Department of Conservation & Natural Resources |issue=4 September 2020 |publisher=Alabama Department of Conservation and Natural Resources |date=4 September 2020 |language=en}}

The Tennessee Valley Authority (TVA) has considered several methods to control the spread of Asian carp, including fish barriers at 10 locks controlled by the TVA. One is a bioacoustics fish fence, which uses a combination of sound, light and air bubbles. These barriers are installed at Barkley Lock and Dam in Kentucky, and are currently being studied for their effectiveness in deterring Asian carp. Other types of barriers used for Asian carp include carbon dioxide and electricity. The TVA has conducted environmental impact studies to minimize the impact of the barriers on native species. The TVA has also considered adjusting flow rates during Asian carp spawning periods, which are usually during high-water events, as Asian carp eggs are only semibuoyant and will sink to the bottom and die with low river flow.

File:Silver carp jumping out of the Illinois River.webm]]

The silver carp is sometimes called the "flying" carp for its tendency to leap from the water when startled; it can leap up to {{convert|10|ft|m|abbr=on}} into the air.{{cite news|author=Moritz, R.|date=7 September 2008|title=Pesky 'flying' carp causing problems in SE Arkansas|url=http://www.arkansasnews.com/archive/2008/09/07/News/347862.html|newspaper=Arkansas News}} Boaters traveling in uncovered high-speed watercraft have been reported to be injured by running into airborne fish while at speed. A leaping silver carp broke the jaw of a teenager being pulled on an inner tube, and water skiing in areas where silver carp are present is extremely dangerous.{{cite news|title=Great Flying Carp! Fish A Threat To Boaters, Skiers|url=http://www.flmnh.ufl.edu/fish/InNews/flyingcarp2004.htm|archive-url=https://web.archive.org/web/20040327022104/http://www.flmnh.ufl.edu/FISH/InNews/flyingcarp2004.htm|url-status=dead|archive-date=27 March 2004|publisher=The Courier-Journal|date=12 March 2004}} Peculiarly, the extreme jumping behavior appears to be unique to silver carp of North America; those in their native Asian range and introduced to other parts of the world are much less prone to jumping. Although theories have been proposed (for example, the high densities the species reaches in parts of North America, or that the introduced North American population may have been based on a small number of particularly "jumpy" individuals), the reason for these geographic differences is not known for certain.{{cite conference | doi=10.1121/2.0000279| title=Broadband sound can induce jumping behavior in invasive silver carp (Hypophthalmichthys molitrix)|volume=27 |issue=1 | pages= 010021| conference=Proceedings of Meetings on Acoustics |series=| year=2016| last1=Vetter| first1=Brooke J.| last2=Mensinger| first2=Allen F.| doi-access=free}}{{cite book | author1=Kolar, K.S. | author2=Chapman, D.C. | author3=Courtenay, W.R. Jr. | author4=Housel, C.M. | author5=Williams, J.D. | author6=Jennings, D.P. | year=2007 | title=Bigheaded carps: a biological synopsis and environmental risk assessment | series=American Fisheries Society Special Publication | volume=33 | isbn=978-1-888569-79-7 }}

{{Reflist|32em}}

{{Commons category|Hypophthalmichthys molitrix}}

• [https://www.invasivespeciesinfo.gov/profile/silver-carp Species Profile - Silver Carp (Hypophthalmichthys molitrix)], National Invasive Species Information Center, United States National Agricultural Library lists general information and resources for silver carp.
• [https://pubs.usgs.gov/fs/2010/3033/ Facts About Invasive Bighead and Silver Carps], United States Geological Survey
• [https://digitalcommons.unl.edu/natlinvasive/5/ Asian Carps of the Genus Hypophthalmichthys (Pisces, Cyprinidae) ― A Biological Synopsis and Environmental Risk Assessment]

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{{DEFAULTSORT:Silver Carp}}

Category:Carp

Category:Hypophthalmichthys

Category:Commercial fish

Category:Game fish

Category:Freshwater fish of China

Category:Fish of East Asia

Category:Fish of Bangladesh

Category:Taxa named by Achille Valenciennes

Category:Fish described in 1845

Category:Cyprinid fish of Asia