View source for Grass carp

{{Short description|Species of fish}}
{{Speciesbox
| name = Grass fish
| fossil_range = {{fossil range|Early Miocene|present}}
| image = Ctenopharyngodon idella 01 Pengo.jpg
| image_caption = 
| status = LC
| status_system = IUCN3.1
| status_ref = <ref>{{cite iucn|author=Bogutskaya, N.|year=2022|title=''Ctenopharyngodon idella''|article-number=e.T61295A3102796|doi=10.2305/IUCN.UK.2022-1.RLTS.T61295A3102796.en|access-date=21 August 2023}}</ref>
| parent_authority = [[Franz Steindachner|Steindachner]], 1866
| taxon = Ctenopharyngodon idella
| display_parents = 2
| authority = ([[Achille Valenciennes|Valenciennes]] in Cuvier & Valenciennes, 1844)
| synonyms = *''Leuciscus idella'' <small>Valenciennes, 1844</small> 
*''Ctenopharingodon idellus'' <small>(Valenciennes, 1844)</small> 
*''Ctenopharyngodon idellus'' <small>(Valenciennes, 1844)</small> 
*''Leuciscus tschiliensis'' <small>Basilewsky, 1855</small> 
*''Ctenopharyngodon laticeps'' <small>[[Franz Steindachner|Steindachner]], 1866</small> 
*''Sarcocheilichthys teretiusculus'' <small>[[Rudolf Kner|Kner]], 1867</small>
*''Pristiodon siemionovii'' <small>[[Benedykt Dybowski|Dybowski]], 1877</small>
}}
{{multiple image
 | align = right
 | direction = vertical
 | width     = 250
 | image1    = 2x amur bílý.jpg
 | alt1      = 
 | caption1  = {{center|Adult grass carp}}
 | image2    = Grass-Carp1web.jpg
 | alt2      = 
 | caption2  = {{center|Juvenile grass carp}}
}}

The '''grass carp''' ('''''Ctenopharyngodon idella''''') is a [[species]] of large [[herbivorous]] [[freshwater fish]] in the [[family (biology)|family]] [[Cyprinidae]], native to the [[Pacific]] [[Far East]], with a [[native range]] stretching from [[northern Vietnam]] to the [[Amur River]] on the [[Sino-Russian border]].<ref name="mandrak2004">Mandrak and Cudmore. 2004. [http://sbisrvntweb.uqac.ca/archivage/24061712.pdf ''Biological Synopsis of Grass Carp (Ctenopharyngodon idella)''] {{webarchive|url=https://web.archive.org/web/20110706211145/http://sbisrvntweb.uqac.ca/archivage/24061712.pdf |date=2011-07-06 }}.</ref> This [[Asian carp]] is the only species of the [[genus]] '''''Ctenopharyngodon'''''.

Grass carp are resident fish of large turbid [[river]]s and associated [[floodplain lake]]s/[[wetland]]s with a wide range of temperature tolerance, and spawn at temperatures of {{convert|20|to|30|C|F}}.<ref name="mandrak2004"/><ref>Shireman, J.V. and C.R. Smith. 1983. ''Synopsis of biological data on the grass carp, Ctenopharyngodon idella (Cuvier and Valentines, 1844)''. Food and Aquaculture Organization Synopsis. 135: 86pp.</ref> It has been [[aquaculture|cultivated]] as a [[food fish]] in [[China]] for centuries, being known as one of the "Four Great Domestic Fish" ({{lang-zh|四大家鱼}}), but was later [[introduced species|introduced]] to [[Europe]] and the [[United States]] for [[aquatic plant management|aquatic weed control]], becoming the fish species with the largest reported [[fish farming|farmed production]] globally, over five million tonnes per year.<ref name=FAO>[https://web.archive.org/web/20170518134921/ftp://ftp.fao.org/FI/STAT/summary/a-6.pdf World aquaculture production of fish, crustaceans, mollusks, etc., by principal species in 2013]  FAO Yearbook of Fisheries Statistics 2014</ref>

== Evolution ==
The grass carp is the only extant member of the genus ''Ctenopharyngodon'', but two other extinct species in the genus are known from [[Early Miocene]]-aged fossil teeth from China: †''[[Ctenopharyngodon orientalis|Ctenopharyngodon]]'' ''[[Ctenopharyngodon orientalis|orientalis]]'' <small>Su, [[Meemann Chang|Chang]] & Chen, 2021</small> ([[Xiacaowan Formation]] of [[Hebei]]) and †''[[Ctenopharyngodon xiejiaensis]]'' <small>Su, Chang & Chen, 2021</small> ([[Xiejia Formation]] of [[Qinghai]]). The earliest fossil teeth of the modern grass carp (''C. idella'') appear in the [[Zanclean|Early Pliocene]]-aged [[Gaozhuang Formation]] of [[Shanxi]]. Two other extinct genera that appear to be related to grass carp, †''[[Eoctenopharyngodon]]'' and †''[[Dezaoia]]'', are known from the [[Oligocene]] of China.<ref>{{Cite journal |last=Su |first=Ruifeng |last2=Chang |first2=Mee-Mann |last3=Chen |first3=Gengjiao |date=2021-11-01 |title=Fossil pharyngeal teeth of grass carp group and their implications for evolution, temporal and spatial distribution pattern, and paleoenvironment |journal=Science China Earth Sciences |language=en |volume=64 |issue=11 |pages=1844–1859 |doi=10.1007/s11430-020-9724-7 |issn=1869-1897}}</ref>

==Appearance and anatomy==
Grass carp have elongated, chubby, torpedo-shaped body forms. The terminal mouth is slightly oblique with non-fleshy, firm lips, and no [[barbel (anatomy)|barbel]]s.<ref name=fishbase>{{FishBase|ID=79|genus=Ctenopharyngodon|species=idella|year=2007|month=May}}</ref> The complete [[lateral line]] contains 40 to 42 scales. Broad, ridged [[pharyngeal teeth]] are arranged in a "2, 4-4, 2" formula. The dorsal fin has eight to 10 soft rays, and the anal fin is set closer to the tail than most cyprinids. Body color is dark olive, shading to brownish-yellow on the sides, with a white belly and large, slightly outlined scales. 
 
Grass carp grow very rapidly. Young fish stocked in the spring at {{cvt|20|cm|in}} will reach over {{cvt|45|cm|in}} by fall. The typical length is about {{cvt|60|–|100|cm|in|round=0.5}}. The maximum length is {{cvt|2.0|m|ft}} and they grow to {{cvt|45|kg|lb}}.

==Ecology==
Grass carp inhabit lakes, [[pond]]s, [[stream pool|pool]]s and [[backwater (river)|backwater]]s of large rivers, preferring large, slow-flowing or standing [[water bodies]] with abundant vegetation.<ref name=fishbase/> In the wild, grass carp spawn in fast-moving rivers, and their eggs, which are slightly heavier than water, develop while drifting downstream, kept in suspension by turbulence. Grass carp require long rivers for the survival of the eggs and very young fish, and the eggs are thought to die if they sink to the bottom.<ref>Krykhtin, M.L., and E.I. Gorbach. 1981. ''Reproductive ecology of the grass carp, Ctenopharyngodon idella, and the silver carp, Hypophthalmichthys molitrix, in the Amur Basin''. Journal of Ichthyology 21(2):109-123.</ref>

Adult grass carps feed primarily on [[aquatic plant]]s, both higher aquatic plants and submerged terrestrial vegetation, but may also eat [[detritus]], [[insect]]s and other [[invertebrate]]s.<ref name="mandrak2004"/><ref name=fishbase/> They eat up to three times their own body weight daily, and thrive in small lakes and backwaters that provide an abundant supply of vegetation.{{citation needed|date=March 2009}}

According to one study, grass carp live 5–9 years, with the oldest surviving 11 years. In [[Silver Lake, Washington]], a thriving population of grass carp is passing the 15-year mark.<ref>Kirk and Socha. [http://www.apms.org/japm/vol41/v41p90.pdf ''Longevity and Persistence of Triploid Grass Carp Stocked into the Santee Cooper Reservoirs of South Carolina''] {{Webarchive|url=https://web.archive.org/web/20110904051611/http://www.apms.org/japm/vol41/v41p90.pdf |date=2011-09-04 }}. J. Aquat. Plant Manage. 41:2003.</ref>

==Introduced species==
Grass carp have been [[introduced species|introduced]] to many countries around the world. In the Northern Hemisphere, countries and territories of introduction include [[Japan]], the [[Philippines]], [[Malaysia]], [[India]], [[Pakistan]], [[Iran]], [[Israel]], the [[United States]], [[Mexico]], [[Sweden]], [[Denmark]], the [[United Kingdom]], [[France]], [[Germany]], the [[Netherlands]], [[Switzerland]], [[Italy]], [[Poland]], the [[Czech Republic]], [[Slovakia]], [[Romania]], [[Croatia]], [[Slovenia]], [[Serbia]], [[Montenegro]], [[Bosnia and Herzegovina]] and [[North Macedonia|Macedonia]]. In the Southern Hemisphere, they have been introduced to [[Argentina]], [[Venezuela]], [[Australia]], [[New Zealand]], [[Fiji]] and [[South Africa]]. Grass carp are known to have spawned and established self-reproducing populations in only six of the many larger Northern Hemisphere rivers into which they have been stocked. Their failure to establish populations in other rivers suggests they have quite specific reproductive requirements.<ref>Rowe, D. K., & Schipper, C. M. (1985). ''An assessment of the impact of grass carp (Ctenopharyngodon Idella) in New Zealand waters''. Rotorua N.Z.: Fisheries Research Division, Ministry of Agriculture and Fisheries.</ref>

In the United States, the species was first imported in 1963 from [[Taiwan]] and Malaysia to aquaculture facilities in [[Alabama]] and [[Arkansas]].<ref name=nico2012/> The first release is believed to have been an accidental escape in 1966 from the [[United States Fish and Wildlife Service|U.S. Fish and Wildlife Service]]'s Fish Farming Experimental Station in [[Stuttgart, Arkansas]], followed by planned introductions beginning in 1969.<ref name=nico2012/><ref name="Simmonds2007"/> Subsequently, authorized, illegal and accidental introductions have been widespread; by the 1970s, the species had been introduced to 40 states, and it has since been reported in 45 of the country's 50 states.<ref name=nico2012>{{ cite web | last1=Nico | first1=L.G. | first2=P.L. | last2=Fuller | first3=P.J. | last3=Schofield | first4=M.E. | last4=Neilson | date=15 March 2012 | title=Grass Carp (''Ctenopharyngodon idella'') | work=Nonindigenous Aquatic Species (NAS) database | publisher=United States Geological Survey | location=Gainesville, FL | url=https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=514 | access-date=12 January 2014 }}</ref><ref name="Simmonds2007"/> In 2013, it was determined to be reproducing in the [[Great Lakes Basin]].<ref name="ChapmanDavis2013">{{ cite journal
 | last1=Chapman
 | first1=Duane C.
 | last2=Davis
 | first2=Jeremiah J.
 | last3=Jenkins
 | first3=Jill A.
 | last4=Kocovsky
 | first4=Patrick M.
 | last5=Miner
 | first5=Jeffrey G.
 | last6=Farver
 | first6=John
 | last7=Jackson
 | first7=P. Ryan
 | title=''First evidence of grass carp recruitment in the Great Lakes Basin''
 | journal=Journal of Great Lakes Research
 | volume=39
 | issue=4
 | year=2013
 | pages=547–554
 | issn=0380-1330
 | doi=10.1016/j.jglr.2013.09.019 | bibcode=2013JGLR...39..547C
 }}</ref> It is still stocked in many states as an effective [[biocontrol]] for undesirable aquatic vegetation,<ref name=nico2012/><ref name="Simmonds2007">{{cite book
 | title=Management and Control Plan for Bighead, Black, Grass, and Silver Carps in the United States
 | date=November 2007
 | editor1=Canover, G
 | editor2=Simmonds, R
 | editor3=Whalen, M
 | publisher=Asian Carp Working Group, Aquatic Nuisance Species Task Force
 | location=Washington, DC
 | pages=21–27
 | url=http://www.anstaskforce.gov/Documents/Carps_Management_Plan.pdf
 | access-date=2008-12-16
 | archive-date=2020-08-11
 | archive-url=https://web.archive.org/web/20200811182113/https://www.anstaskforce.gov/Documents/Carps_Management_Plan.pdf
 }}</ref> many species of which are themselves introduced.

==Use==
===Weed control===
Grass carp were introduced into New Zealand in 1966 to control the growth of aquatic plants. Unlike the other introduced fish brought to New Zealand, the potential value and impact of grass carp was investigated in secure facilities prior to their use in field trials.<ref>[http://www.niwa.co.nz/freshwater-and-estuaries/nzffd/NIWA-fish-atlas/fish-species/grass_carp ''Grass carp''] in ''niwa.co.nz''.</ref> They are now approved by the New Zealand government for aquatic weed control, although each instance requires specific authorization.<ref name=weed>[http://www.doc.govt.nz/get-involved/apply-for-permits/interacting-with-freshwater-species/options-for-weed-control/grass-carp/ "Grass carp for weed control"], DOC</ref> In the Netherlands, the species was also introduced in 1973 to control over-abundant aquatic weeds. The release was controlled and regulated by the Dutch [[Ministry of Agriculture, Nature and Food Quality (Netherlands)|Ministry of Agriculture, Nature, and Food Quality]]. In both of these countries, control is made easier because grass carp are very unlikely to naturally reproduce because of their very specific breeding requirements,<ref name=weed/> but elsewhere, control is obtained by the use of sterile, [[polyploidy|triploid]] fish.<ref name="Simmonds2007"/><ref>[http://tpwd.texas.gov/landwater/water/habitats/private_water/gcarp.phtml "Triploid Grass Carp Information"], texas.gov</ref>

===Food===
[[File:Grass carp(=white amur), aquaculture production, million tonnes, 1950-2022.svg|thumb|Global aquaculture production of grass carp (''Ctenopharyngodon idella'') in million tonnes from 1950 to 2022, as reported by the [[Food and Agriculture Organization|FAO]]<ref>FAO. 2024. Global Production. In: ''Fisheries and Aquaculture''. Published March 29th, 2024. https://www.fao.org/fishery/en/collection/global_production?lang=en</ref>]]
Grass carp is one of the most common freshwater farmed fish in China, being one of the Four Domestic Fish ''(四大家鱼)'' alongside the [[black carp]], [[silver carp]], and [[bighead carp]]. Its meat is tender, with little bones. Many [[Chinese cuisine]] has grass carp as a featured dish, such as [[Cantonese cuisine]].<ref>{{cite web |title=Cantonese Steamed Fish: A 20 Minute Recipe |url=https://thewoksoflife.com/cantonese-steamed-fish/ |website=The Woks of Life |access-date=3 February 2023 |date=20 December 2020}}</ref> In some Asian countries, it is believed that ingestion of raw bile or entire gall bladders of the grass carp may improve visual acuity and health. However, it may in fact cause severe poisoning.<ref name="Cho_2013">{{cite journal | vauthors = Cho YD, Yoon YH, Choi SH, Park SM, Kim JY| title = Acute hepatitis and acute kidney insufficiency caused by ingestion of raw grass carp gall bladder | journal = Emergency Medicine Australasia | volume = 25 | issue = 6 | pages = 608–609| date = 2013 | doi = 10.1111/1742-6723.12137|url=|pmid = 22140646 | pmc= 3228382}}</ref>

==Fishing for grass carp==
[[File:Grass carp 1.jpg|thumb|{{center|A grass carp caught on [[monofilament fishing line]]}}]]
Grass carp grow large and are strong fighters when hooked on a line, but because of their vegetarian habits and their wariness, they can be difficult to catch via [[angling]].<ref>[http://mdc4.mdc.mo.gov/Documents/18513.pdf ''Catching Grass Carp''] {{webarchive|url=https://web.archive.org/web/20100528130729/http://mdc4.mdc.mo.gov/Documents/18513.pdf |date=2010-05-28 }}. Missouri Department of Conservation.</ref> The [[IGFA]] World record for a grass carp caught on line and hook is {{cvt|39.75|kg}}, caught in [[Bulgaria]] in 2009.<ref>[http://wrec.igfa.org/WRecordsList.aspx?lc=AllTackle&cn=Carp,%20grass "Grass carp"], [[IGFA]] Online. Retrieved 22 June 2016.</ref> The fish are also popular [[sport fish]] in areas where [[bowfishing]] is legal.

Where grass carp populations are maintained through [[fish stocking|stocking]] as a biocontrol for noxious weeds, fishermen are typically asked to return any caught to the water [[catch and release|alive and unharmed]].

==References==
{{reflist|32em}}

==External links==
{{commons category|Ctenopharyngodon idella}}
* [https://www.invasivespeciesinfo.gov/profile/grass-carp Species Profile - Grass Carp (''Ctenopharyngodon idella'')], National Invasive Species Information Center, [[United States National Agricultural Library]]. Lists general information and resources for Grass Carp.
*{{FishBase genus|genus=Ctenopharyngodon}}
* {{ITIS |id=163537 |taxon=Ctenopharyngodon idella |access-date=11 March 2006}}

{{carp|state=expanded}}
{{commercial fish topics}}
{{taxonbar|from=Q76098}}

[[Category:Carp|grass carp]]
[[Category:Commercial fish]]
[[Category:Freshwater fish of China]]
[[Category:Fish of East Asia]]
[[Category:Herbivorous vertebrates]]
[[Category:Taxa named by Achille Valenciennes]]
[[Category:Fish described in 1844|grass carp]]
[[Category:Xenocyprididae]]
[[Category:Chinese seafood]]