Grass carp

The grass carp ("Ctenopharyngodon idella") is a very big herbivorous and freshwater fish species of the familyfamily Cyprinidae. It is from east Asia native to eastern Asia. It was originally found 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 used in China for food. It was introduced in Europe and the United States to help weed control underwater. This species of fish has the biggest production in aquaculture in the world. Over five million tonnes per year are sold.