Using New Genetic Techniques to Raise Bigger Yellow Perch

With the help of genetics, Ohio fish farmers will be able to raise the crème de la crème of yellow perch -- the state’s No. 1 food fish -- with the potential to increase production efficiency up to 50 percent over current growth standards.

Ohio State University aquaculturists with OSU South Centers at Piketon are analyzing the genetic traits of yellow perch lines then cross-breeding those exhibiting high-growth rates and little genetic similarities. After two years of research, data of first generation crosses have shown the fish grew 28 percent to 54 percent faster than the unimproved fish. The goal of the research is to genetically improve broodstocks of yellow perch -- a species that lags in growth.

“Yellow perch is an important fish species for Ohio’s aquaculture industry, but a major problem for the yellow perch industry is the relatively slow growth of currently cultured populations of this species,” said Han-Ping Wang, director of the Ohio Aquaculture Research and Development Integration Program. “Our goal is to help farmers raise bigger fish. Bigger fish means more dollars.”

Wang and his colleagues are accomplishing this task using a state-of-the-art aquaculture facility and new genetic marker technology that improve upon traditional breeding methods. The Aquaculture Genetics and Breeding Lab at Piketon, the first of its type in the Midwest, enables researchers to track the pedigree of the parents to the offspring so when genetically unrelated fish exhibiting the best growth characteristics are bred, the genetics showcasing those traits can be traced back to the source.

It’s a step-up from traditional selection where fish are bred without any knowledge of their genetics, said Wang, a researcher with the Ohio Agricultural Research and Development Center.

“For traditional selection, to raise 150 fish families, you have to have 150 individual tanks, but that’s not possible. With marker technology, all families can be communally raised in the same pond or tank. When fish are raised to harvest size, the best fish or candidates from different families can be identified with parentage analysis by using genetic tags,” said Wang. “Inbreeding can be a big problem if fish are being crossed without knowing their genetics. This reduces the growth rate instead of improving the growth rate.”

Now, researchers are able to develop genetic charts and compare the genetic fingerprint of the offspring with its parents, so that traits for improved growth remain intact for breeding the next generation. So far, researchers have distributed nearly 60,000 improved perch fry and fingerlings to Ohio farmers using this method.

Researchers are also using new equipment that dramatically slashes the time it takes to map the genetics of yellow perch lines. Known as a Genetic Analyzer, the equipment has the capability of fingerprinting 800 broodfish for constructing the genetic pedigrees in two weeks. By comparison, using the traditional equipment, known as electrophoresis or a gel system, would take three months.

The Ohio Genetic Improvement of Farmed-Fish Traits (O’GIFT) Program and the Genetic Analyzer were funded by the U.S. Department of Agriculture Cooperative State Research, Education, and Extension Service and Ohio State University’s Ohio Agricultural Research and Development Center.

Under the O’GIFT Program, researchers are studying yellow perch lines from Ohio, North Carolina, Pennsylvania, Maine, New York, Nebraska, Wisconsin and Michigan. The 10-year project not only includes yellow perch genetic selection, but also research on genetic mapping and muscle development for food fish production.

According to the 2005 USDA Census of Aquaculture, yellow perch accounted for the largest portion of food fish sales in Ohio with 25 farms selling $222,000 worth of fish for an average price of $3.12 per pound. Ohio ranks No. 1 in the nation in sales of yellow perch, and is an integral part of Ohio’s robust aquaculture industry, nearly doubling from nearly $1.8 million in 1997 to over $3.3 million in 2006.