The grass carp (Ctenopharyngodon idella) is a large, herbivorous, freshwater fish species of the family Cyprinidae native to eastern Asia, with an original range from northern Vietnam to the Amur River on the Siberia-China border.This Asian carp 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, becoming the species of fish with the largest reported production in aquaculture globally, over five million tonnes per year.The grass carp is a fish of large, turbid rivers and associated floodplain lakes, with a wide degree of temperature tolerance. Grass carp enter reproductive condition and spawn at temperatures of 20 to 30 °C (68 to 86 °F).
Grass carp have elongated, chubby, torpedo-shaped body forms. The terminal mouth is slightly oblique with nonfleshy, firm lips, and no barbels. 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.