Genetic and Population Characteristics of Walleyes in the Mobile Drainage of Alabama

Mitochondrial DNA (mtDNA) analysis conducted on walleyes Stizostedion vitreum collected in Alabama indicated that 44 fish from the Mobile drainage were of the recently described southern haplotype, whereas all 5 fish from the Tennessee River had a northern haplotype. No successful establishment of female walleyes from Ohio stocked in the Mobile drainage between 1973 and 1985 was indicated by the mtDNA data. However, 3 of 22 loci screened by protein electrophoresis were polymorphic in Alabama walleyes, and three fish in the western portion of the Mobile drainage possessed alleles more typically seen in northern walleyes. These three fish could be descendants of stocked northern male walleyes or individuals with northern alleles that resulted from hybridizations with northern walleyes that had entered the western Mobile drainage via the Tennessee–Tombigbee Waterway. Southern walleyes in Alabama grow rapidly and reach harvestable size (356 mm) by age-2. The largest walleye collected for this study was 601 mm in total length and weighed 2.73 kg; the oldest fish was 9 years old. Females grew faster than males. At Hatchet Creek, spawning success appeared to be greater during springs with cooler weather. Walleyes from Hatchet Creek on the Coosa River appear to be “pure” southern walleyes and are recommended as a source of broodfish for captive breeding programs designed to conserve the southern strain.