What is "grass carp"

The grass carp (Ctenopharyngodon idella) is the species of fish with the largest reported production in aquaculture globally, over five million tonnes per year. It is a large herbivorous freshwater fish species of the family Cyprinidae native to eastern Asia, with a native range from northern Vietnam to the Amur River on the Siberia-China border. It is the only species of the genus Ctenopharyngodon.

It is cultivated in China for food, but was introduced in Europe and the United States for aquatic weed control. It is a fish of large, turbid rivers and associated floodplain lakes, with a wide degree of temperature tolerance. Grass carp will enter reproductive condition and spawn at temperatures of .

In the United States, the fish is also known as white amur, which is derived from the Amur River, where the species is probably native, but has never been abundant. This is not to be confused with the white Amur bream (Parabramis pekinensis), which is not a particularly close relative.