Grass carp ( Ctenopharyngodon idella Val.) in North America

Abstract

The grass carp, Ctenopharyngodon idella Val., was introduced into Mexico in 1960 and into the United States in 1963 primarily for aquatic weed control purposes. Natural reproduction has occurred in Mexico, but not in the United States even though the fish has been present in the Mississippi River system for several years. The grass carp is routinely used in Arkansas for control of weeds and no permit is required for possession of the fish in Alabama, Iowa, and South Dakota. Canada and over half of the states in the United States have banned the grass carp, with the remainder either regulating the fish by permits or having as yet made no decision. A number of studies are in progress on the use of the grass carp for aquatic weed control and its subsequent impact on the aquatic ecosystem. Management of the number and size of fish in a given body of water will be the primary factor to consider in using the grass carp for control of certain aquatic weeds.