Common Name: Bighead Carp - This fish may also be referred to as noble fish, speckled amur, or lake fish.

Scientific Name: Hypophthalmichthys nobilis
The bighead carp was formerly known as Aristichthys nobilis but that is no longer its accepted scientific name. It belongs to the Cyprinidae family, which is the carp and minnow family.

DISTRIBUTION: The bighead carp is a native fish of China. Currently this fish has expanded its range to include the United States. Bighead carp can be found in or bordering Alabama, Arizona, Arkansas, California, Colorado, Florida, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Minnesota, Missouri, Mississippi, Ohio, Oklahoma, Nebraska, South Dakota, Tennessee, Texas and West Virginia.

DESCRIPTION: The body of a bighead carp is laterally compressed with the top being a dark gray color which grades down to off white on its belly. It has many dark blotches on its sides. Its head is comparatively large with no scales and a large terminal mouth. The bighead fish has no teeth and its lower jaw protrudes out farther than its upper jaw. The eyes are situated lower on its head and are positioned downward. The scales of a bighead carp are small and resemble the scales of a trout. This species is very similar to another Asian carp the silver carp but they can be distinguished by the fact that the bighead carp has many dark blotches on its sides and the silver carp does not. Indiana's record bighead carp weighed 53 lbs 8 oz. The world record bighead carp was 73 lbs 8 oz and 56 inches long with a girth of 35 inches.

PATHWAYS/HISTORY: In 1972 a private fish farmer from Arkansas imported bighead carp to control aquatic weeds in his ponds. Beginning in the early 1980's bighead carp were being found in the open waters of the Ohio and Mississippi Rivers. It is likely that the fish in these rivers were escapees from an aquaculture facilities and farm ponds. One such event where several bighead carp escaped from a facility was in Missouri in 1994. A flood caused the fish to escape into the Osage River. These fish spread to the Kansas River and the Missouri River. It is reported that bighead carp spawn in the Missouri, Illinois and Mississippi River's. Currently there are carp in the Chicago Ship and Sanitary Canal, which connects the Mississippi River and Lake Michigan. It is estimated that bighead carp are 40 miles away from entering the Great Lakes system.

DISPERSAL/SPREAD: Bighead carp were imported into the country to clean up aquaculture ponds by filtering the water. Floods in the areas of these stocked ponds facilitated the release of the bighead carp into open waters. Once in open waters they began to spawn and disperse themselves. Other ways that the bighead carp could have spread is bait release and release to establish a food source. Juvenile bighead carp are a popular bait item but using them in this way enhances their ability to establish in new areas. This fish is very important to the Asian culture and is readily sold in Asian markets so it is thought that some introductions of bighead carp were to establish a local food source.

MANAGEMENT: Stopping the spread of the bighead carp is a main management objective. A few things that can be done to help stop the spread of bighead carp are; learn how to correctly identify this invasive species, properly dispose your bait on land and never in water, always drain water from your boat, livewell and bilge before leaving the waters access, never dump fish from one body of water to another, and report new sightings of bighead carp to a Fisheries Biologist. One major concern that biologists have is how this fish will impact the Great Lakes if it enters their waters? To stop the carp from reaching the edge of Lake Michigan the U.S. Army Corps of Engineers built an electrical barrier in the Chicago Ship and Sanitary Canal. Tests have shown that Asian carp flee from noise and bubbles.

LIFE CYCLE BIOLOGY AND LIFE HISTORY: Bighead carp is an exclusively freshwater fish. They prefer large rivers and will not spawn in still water or small streams but do inhabit lakes and ponds. Spawning occurs after spring rains have flooded the river and when the temperature of the water reaches 77o F. External fertilization takes place and the eggs float downstream. Bighead carp grow rapidly and after they reach maturity they are able to gain a pound or more per month. They feed on zooplankton but they are opportunistic feeders, meaning if zooplankton levels are low they will eat phytoplankton and detritus. They filter the water through their comb-like gill rakers so they only consume those organisms small enough to penetrate their filter feeding apparatus.

RISKS/IMPACTS: The main fear that biologist have in regards to the bighead carp is that it consumes the exact food that our native filter feeders eat as well as what most juvenile fish eat. Because the bighead carp can reach such a large size they put extreme pressure on zooplankton populations. This loss of food for our native species could result in their population declines. Bighead carp especially affect paddlefish, bigmouth buffalo, gizzard shad and native mussels. Also declines in the zooplankton population can result in eutrophication of smaller ponds. These fish also pose an economic threat. In areas where bighead carp are so numerous, they are fouling the nets of commercial fisherman to the point where they can no longer lift their nets and are forced to abandon those fishing spots. Bighead carp is also a main food source for the Asian community. Worldwide bighead carp ranks fourth in total production. With the Asian American population on the rise there is more and more pressure for Asian markets in the U.S. to supply bighead carp.

REFERENCES:
- Asian Carp. 11 Nov 2002. U.S. Fish and Wildlife Service. 27 May 2004.
- Asian Carp:A Key To Identification. 15 Nov 2002. U.S. Fish and Wildlife Service. 27 May 2004.
- Bighead Carp. Bow Fish Iowa. 16 July 2004.
- http://www.kansasfishes.com/pages/bigheadcarp.htm (defunct). Kansas Fishes.com. 16 July
  2004.
- Factsheets: Asian Carp. Dec 2003. Pennsylvania Sea Grant. 16 July 2004.
- Hypophthalmichthys nobilis (Richardson, 1845). 21 Nov 2003. Gulf States Marine Fisheries
  Commission. 16 July 2004.
- Nico, Leo. Hypophthalmichthys nobilis (Richardson, 1845). 6 Feb 2004. U.S. Geological Survey.
  16 July 2004.
- Schabath, Gene. Environmentalists fear bighead carp. The Detroit News. 16 July 2004.
- Sharp, Eric Beware big fish: Asian carp are threat to lakes. 11 April 2002. Detroit Free Press. 16
  July 2004.
- Stone, Nathan, Carole Engle, David Heikes and Donald Freeman. Bighead Carp. Sep 2000.
  Southern Regional Aquaculture Center. 16 July 2004.