Historical and Contemporary Gene Flow and the Genetic Structure of Muskellunge in the Ohio River Drainage

Muskellunge Esox masquinongy is a recreationally important species distributed throughout the Ohio, upper Mississippi, and Great Lakes drainages and has been introduced outside of its native range. We conducted a survey of microsatellite DNA variation among 11 populations, natural, managed, and hatchery, in the Ohio River drainage. Microsatellite DNA variation was highly significant among all populations. A CLUSTER analysis identified K = 2 populations corresponding to populations east and west of the Ohio River. This may be a consequence of different management practices by Ohio and West Virginia or may suggest that the Ohio River is a substantial barrier to gene flow. A comparison of historical and contemporary gene flow suggests little change in genetic exchange among populations. Our results further support the use of locally adapted broodstock in further management and supplementation of Muskellunge populations.