USGS Home
Contact USGS
Search USGS

Search fish passage bibliography

White, M. M. and S. Schell (1995). An evaluation of the genetic integrity of Ohio River walleye and sauger stocks. Pages 52-60 in H. L. Schramm, Jr. and R. G. Piper, eds. International Symposium and Workshop on Uses and Effects of Cultured Fishes in Aquatic Ecosystems, Albuquerque, New Mexico (USA), American Fisheries Society.

An electrophoretic survey of populations of walleye Stizostedion vitreum and sauger S. canadense from the Ohio River was conducted to determine the patterns of genetic variation, population structuring, and the degree of hybridization between these two species and their stocked F₁ hybrid, the saugeye (female walleye x male sauger). Thirty-six presumptive structural loci were surveyed from the eye, liver, and muscle tissue of 500 sauger from nine locations and 222 walleyes from seven locations. Levels of variation in sauger were low and suggested limited population differentiation along the river. Levels of variation among walleye populations suggested a significant degree of population differentiation; however, no clear pattern of differentiation was observed. Two polymorphisms, not previously observed in walleye populations, are shared with sauger, suggesting past hybridization events or geographically unique alleles. Recombinant genotypes were detected in samples from three Ohio River pools, confirming that hybrid reproduction has occurred. These three pools are consecutively affected by one major river and four smaller watersheds that have received large numbers of stocked saugeyes. If maintaining the genetic integrity of the parental species is a concern, our data strongly suggest that saugeye should not be stocked where self-sustaining parental populations occur.