05/25/2002

Growing a Better Catfish

AUBURN–If you purchase catfish at your local grocery or restaurant, chances are you're buying farm-raised catfish. And the chances are good that your meal was raised in Alabama and that Auburn University had a hand in its growth.

Alabama is one of the top four catfish-producing states, which together accounted for 95 percent of the United States' total sales in 2001. The catfish industry includes both large and small family farms and is critical for the economic viability of many communities in Alabama and the South.

To keep this industry growing, Auburn University scientists in the Department of Fisheries and Allied Aquacultures are developing a hybrid catfish that could increase farm profitability by decreasing production costs and improving efficiency.

The mating or crossing of two different species is a process called hybridization, with the offspring known as hybrids. Hybrids between different species of North American catfish have been researched for more than 30 years. Of all these interspecific catfish hybrids (crosses between two distinct species) only one hybrid has characteristics that favor commercial application. That hybrid is a cross between female channel catfish and male blue catfish.

Traits that influence profitability of a commercial catfish farm include growth rate, overall survival, meat yield, disease resistance and harvestability. Research trials demonstrated that blue/channel catfish hybrids exhibit good performance for these traits, which has spawned interest in commercial culture of hybrid catfish.

"The more traits that we examine, the more we learn that this catfish hybrid is an especially valuable fish because with one simple breeding technique, we improve about eight different traits," said Rex Dunham, fisheries professor and head of the AU Peaks of Excellence hybrid catfish initiative program in Alabama.

However, there are problems with the production of hybrid embryos. One is that the two parent species will not readily spawn in ponds. Another is the current lack of blue catfish brood stock, since virtually all of the catfish industry is based on channel catfish.

AU researchers are working on problems in artificial spawning and fertilization techniques that are hampering the mass production of these hybrids. Scientists are evaluating hormone treatments that induce females to release eggs to maximize production of hybrid eggs and the hatching rate of fertilized eggs. And they are developing technology to more efficiently utilize the sperm from donor males to fertilize the eggs.

"Once we have some of these reproductive problems ironed out a little bit better and farmers adopt the new spawning strategies, it's going to be a major advancement in the catfish industry," said Dunham. "The impact of this fish will be tremendous. Limited field studies showed that this hybrid, even with the increased hatchery costs, could increase farm profitability from 20 to 100 percent."

Fisheries and Aquaculture is one of seven multi-disciplinary research initiatives at Auburn designated as Peaks of Excellence. Research from the hybrid catfish initiative exemplifies the Peaks programs at work improving life for Alabama citizens.

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News from:

Office of Ag Communications & Marketing

Auburn University College of Agriculture
Alabama Agricultural Experiment Station
3 Comer Hall, Auburn University
Auburn, AL 36849
334-844-4877 (PHONE) 334-844-5892 (FAX)

Contact Jamie Creamer, 334-844-2783 or jcreamer@auburn.edu
Contact Leigh Hinton, 334-844-5886 or hintola@auburn.edu

May 2002