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Science & Nature • Ichthyology

Grass carp

The grass carp (*Ctenopharyngodon idella*) is a large freshwater fish in the family Cyprinidae, native to eastern Asia.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 27, 2026|2 min read| Fact-checked

The grass carp (Ctenopharyngodon idella) is a large freshwater fish in the family Cyprinidae, native to eastern Asia. It has been widely cultivated as a food fish and introduced in many countries for aquatic weed control, where it can also become invasive. It is the only species in the genus Ctenopharyngodon.

Taxonomy and naming

Grass carp is the species Ctenopharyngodon idella in the family Cyprinidae. It is the only species placed in the genus Ctenopharyngodon and is also known as white amur.

Distribution and habitat

The species is native to eastern Asia, including major river systems in China, Russia, and Vietnam. It inhabits large rivers, lakes, and reservoirs, and has been introduced widely beyond its native range.

Ecology and diet

Grass carp are herbivorous freshwater fish that feed mainly on aquatic plants, though they may also consume other organic material. Their feeding can remove large amounts of vegetation and alter aquatic habitats.

Human use and introduction

Grass carp have been cultivated in China for centuries as a food fish and are widely used elsewhere for aquatic weed control. Introductions have made the species invasive in some areas, including parts of North America.

Economic and environmental significance

The species is important in aquaculture and water management, but its impacts can be mixed. In non-native ecosystems, heavy grazing can reduce native vegetation and affect water quality and habitat structure.

Key facts

  • The grass carp is a large freshwater fish and one of the largest members of the minnow family.
  • It is native to rivers and lakes in eastern Asia and feeds mainly on aquatic vegetation.
  • The species is widely farmed and has been reported as the most-produced fish species in aquaculture globally.
  • It is used for biological control of aquatic weeds but can become invasive outside its native range.
  • Grass carp is monitored as an aquatic invasive species in Canada, affecting freshwater ecosystems.
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Canadian context

Grass carp is relevant to Canadian readers because it is monitored as an aquatic invasive species and can affect freshwater ecosystems and water-management programs. Canadian federal sources note its potential to uproot vegetation and reduce water quality.

Frequently asked questions

What is the grass carp?
The grass carp is a large freshwater fish species, Ctenopharyngodon idella, in the minnow family Cyprinidae.
Where is the grass carp native to?
It is native to eastern Asia, including river systems from northern Vietnam to the Amur River region.
What does grass carp eat?
It feeds primarily on aquatic plants, although it may also consume other organic material when available.
Why are grass carp introduced to waterways?
They are introduced mainly to control aquatic weeds and manage excessive vegetation in ponds, reservoirs, and fish farms.
Is grass carp invasive?
Yes, it can be invasive outside its native range because it may heavily reduce aquatic vegetation and alter habitats.
Is grass carp farmed for food?
Yes, it has been cultivated as a food fish in China for centuries and is widely farmed globally.

References

  1. Wikipediahttps://en.wikipedia.org/wiki/Grass_carp
    Supports: Scientific name, family, native range, genus, and general description.
  2. Fisheries and Oceans Canadahttps://www.dfo-mpo.gc.ca/species-especes/profiles-profils/grasscarp-carperoseau-eng.html
    Supports: Identification features, feeding on aquatic vegetation, and ecological impacts.
  3. U.S. Fish and Wildlife Servicehttps://icrcc.fws.gov/apps/invasive-carp/grass-carp
    Supports: Native range, size, diet, lifespan, and establishment in the United States.
  4. U.S. Geological Surveyhttps://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=514
    Supports: Scientific name, synonyms, native range, identification, and common names.
  5. Food and Agriculture Organization of the United Nationshttps://www.fao.org/fishery/docs/CDrom/aquaculture/I1129m/file/en/en_grasscarp.htm
    Supports: Native Chinese range, introductions to other countries, habitat, and aquaculture use.
  6. Wisconsin Sea Granthttps://www.seagrant.wisc.edu/our-work/focus-areas/ais/invasive-species/invasive-species-fact-sheets/fish/grass-carp/
    Supports: Introduction history in the U.S., weed-control use, and invasive impacts.