grass carp

Grass carp have elongated, chubby, torpedo-shaped body forms. The terminal mouth is slightly oblique with non-fleshy, firm lips, and no barbels.{{FishBase|ID=79|genus=Ctenopharyngodon|species=idella|year=2007|month=May}} 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}}.

Grass carp inhabit lakes, ponds, pools and backwaters of large rivers, preferring large, slow-flowing or standing water bodies with abundant vegetation. 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.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.

Adult grass carps feed primarily on aquatic plants, both higher aquatic plants and submerged terrestrial vegetation, but may also eat detritus, insects and other invertebrates. 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.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.

Grass carp have been 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 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.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.

In the United States, the species was first imported in 1963 from Taiwan and Malaysia to aquaculture facilities in Alabama and Arkansas. The first release is believed to have been an accidental escape in 1966 from the U.S. Fish and Wildlife Service's Fish Farming Experimental Station in Stuttgart, Arkansas, followed by planned introductions beginning in 1969. 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.{{ 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 }} In 2013, it was determined to be reproducing in the Great Lakes Basin.{{ 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

}} It is still stocked in many states as an effective biocontrol for undesirable aquatic vegetation,{{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

| url-status=dead

}} many species of which are themselves introduced.

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.[http://www.niwa.co.nz/freshwater-and-estuaries/nzffd/NIWA-fish-atlas/fish-species/grass_carp Grass carp] in niwa.co.nz. They are now approved by the New Zealand government for aquatic weed control, although each instance requires specific authorization.[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 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. 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, but elsewhere, control is obtained by the use of sterile, triploid fish.[http://tpwd.texas.gov/landwater/water/habitats/private_water/gcarp.phtml "Triploid Grass Carp Information"], texas.gov

File:Grass carp(=white amur), aquaculture production, million tonnes, 1950-2022.svgFAO. 2024. Global Production. In: Fisheries and Aquaculture. Published March 29th, 2024. https://www.fao.org/fishery/en/collection/global_production?lang=en]]

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. {{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}} 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.{{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}}

File:Grass carp 1.jpg}}]]

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.[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. The IGFA World record for a grass carp caught on line and hook is {{cvt|39.75|kg}}, caught in Bulgaria in 2009.[http://wrec.igfa.org/WRecordsList.aspx?lc=AllTackle&cn=Carp,%20grass "Grass carp"], IGFA Online. Retrieved 22 June 2016. The fish are also popular sport fish in areas where bowfishing is legal.

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

{{reflist|32em}}

{{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}}

grass carp

Category:Commercial fish

Category:Freshwater fish of China

Category:Fish of East Asia

Category:Herbivorous vertebrates

Category:Taxa named by Achille Valenciennes

grass carp

Category:Xenocyprididae

Category:Chinese seafood