Hybrid Striped Bass

Arthcle Reprint:  See http://www.agmrc.org/agmrc/commodity/aquaculture/hybridstripedbass/

By Dan Burden, content specialist, AgMRC, Iowa State University, djburden@iastate.edu 

Profile revised January 2007.

Overview 

Hybrid striped bass are a laboratory cross between striped bass (rockfish) (Morone saxatilis) and white bass (Morone chrysops). The crosses also are know as “wipers.” Hybrid striped bass are not capable of reproducing with one another; however, they may backcross with either striped bass or white bass. Hybrids of this type are produced for their fast growth rate, generally increased harvestable size and offspring vigor. The parent species, as well as the hybrid offspring, are voracious predators and are fed high-protein, grain-based diets to prevent rampant cannibalization in closed production systems.

Striped Bass

When they are breeding migrants in freshwater, striped bass are anadromous fish associated with coastal streams. Otherwise, they are coastal saltwater residents. In landlocked freshwater systems, striped bass may run from a lake into a river system, spending the majority of their life cycle in the larger body of water but returning to freshwater streams to spawn. They occur along the Atlantic coast from the St. Lawrence River to the St. Johns River, Florida, as well as the Gulf of Mexico and tributaries in Alabama, Mississippi and Louisiana. They are an important recreational fish species in the United States and have been introduced into many large reservoir systems as a sport fish.

White Bass

The distribution of white bass includes the St. Lawrence River west through the Great Lakes states from New York to Minnesota, west to South Dakota and south in the Ohio and Mississippi valleys to the Gulf of Mexico. Its natural range has been greatly enhanced as a result of sport-fish stocking programs. White bass are generally found in schools in large streams, lakes and reservoirs. They prefer clear water and tend to be found over sand, rock or gravel bottoms. Spawning begins in the spring as water temperatures approach 55°F to 60°F. A single female may produce up to 500,000 eggs.

Production

Currently, production of hybrid striped bass usually begins with “in-house” brood stock or with fingerlings purchased from other producer’s rearing facilities. Fingerlings are reared at 79°F in hard water at a pH maintained at between 6.5 and 8.5 with a dissolved oxygen level above 6.0 ppm. Most hybrids are tank reared, although there is some interest in rearing them in ponds in the southern states.

Hybrid striped bass “wipers” are cultured in private facilities mainly for supply to the restaurant and supermarket trade as a food fish or a fresh or frozen, filleted product. Much is sold as a “whole-fresh” product to high-end restaurants and some is exported by air-freight to European markets. Properly frozen fish have a shelf life of up to four months.

Hybrid striped bass production is rapidly expanding in the United States. Annual production has increased from about 400,000 pounds in 1987 to about 11 million pounds in 2005. According to the latest Census of Aquaculture, 67 of the 87 farms raising hybrid striped bass in 2005 emphasized the production of foodsize striped bass, with total sales of $27.7 million. A much smaller number of farms, a total of 17, raised stockers. Production growth is a response to some reduction in natural fishery stocks of striped bass, generally increased urban-based market demand for seafood and the development of improved culture techniques for this species. Other countries, including Taiwan, Israel and Italy, have extensive, expanding production systems.  (Source: Ludwig, G.M., 2004, Hybrid Striped Bass Production: Fingerling Production in Ponds, SRAC, Publication No. 302; http://srac.tamu.edu/302fs.pdf)