The existence of a distinct walleye (Stizostedion vitreum) population in south-flowing drainages of the southeastern United States has been suspected for some time. Recently, a mitochondrial-DNA (mtDNA) marker was identified that permitted discrimination of these southern walleyes from northern forms. In order to determine the type and distribution of walleyes in Alabama, mtDNA analysis was conducted on 35 individuals collected from 3 river systems within the state. Thirty-one fish collected in the Mobile Basin were the southern form of walleye, which previously had been identified only in northeastern Mississippi, while 4 fish from the Tennessee River were of the northern form. There was no evidence for the successful establishment of any female walleyes from Ohio that were stocked into 2 impoundments in the Mobile Basin 10-20 years ago. Additional surveys and a careful monitoring program using genetic markers should be implemented to detect any infusion of northern walleyes into the Mobile Basin through the Tennessee-Tombigbee Waterway.
