There are two genetically distinct strains of Walleye (Sander vitreus) native to Kentucky watersheds: The Northern, or Lake Erie strain, and the Eastern Highlands strain. A genetically distinct subset of the Eastern Highland strain is known as Rockcastle River strain. Previously, stocking efforts in Kentucky caused Lake Erie strain to enter the Eastern Highland strain’s native range, and their F1 hybrids. Walleye is an extremely popular sportfish in Kentucky, as well as an important predator within Kentucky waterway ecosystems. It is critical that Walleye populations be efficiently managed for the health of Kentucky’s watersheds and its recreational fishing industry. The goal of this work was to identify and compare different methods of strain identification for Walleye, so that stocking can better match the intended genetics of a population. The objectives were to: (i) review literature on molecular genetics and current knowledge for identification of Walleye strains, and (ii) discuss future work building on advancements in molecular genetics for effective management of native Kentucky Walleye populations. Microsatellite analysis has been the preferred method for identifying Walleye strains, but single-nucleotide polymorphism (SNP) assay was recently developed and used in strain identification (2023, 2024) that reduced the time needed to identify strain and that reported improved accuracy at identifying the two strains, and their F1 and F2 hybrids. The SNP method of strain identification may be at the forefront of genetic identification, but further studies are needed to evaluate capabilities and cost of microsatellite and SNP identification methods. Currently, broodstock used by Kentucky fish and wildlife were bred from Rockcastle River strain. A quick, cost-effective, reliable way to differentiate Lake Erie, Eastern Highlands, and Rockcastle River walleye strains would contribute to assessing and to better understanding of the Walleye populations in Kentucky, and increased efficiency in stocking and management efforts.
Acknowledgments: We would like to acknowledge Jay Herrala, Fisheries Program Coordinator, and Josh Pennington, Fish and Wildlife program manager of the Kentucky Department of Fish and Wildlife for their help with this project.