the purpose of this study is to determine the population genetic and phylogeographic structure of aplodinotus grunniens (freshwater drum) populations through analysis of the nadh dehydrogenase subunit 2 (nd2) region and the control region of mitochondrial dna. hypotheses were formed regarding genetic variation in freshwater drum, identification of regions where freshwater drum survived glaciation, and source populations and colonization routes. primers specific to the nd2 and control regions of freshwater drum were developed and genetic analysis performed. genetic data were analyzed to assess relationships within and between populations.