Evolutionarily significant units of rare pygmy sunfishes (genus Elassoma)

Mitochondrial and nuclear gene variation is described from populations repr esenting the range of two species of rare pygmy sunfishes, Elassoma boehlke i and Elassoma okatie, in the Carolinas. Mitochondrial control region seque nces provide evidence for a minimum of four Evolutionarily Significant Unit s (ESU), two each within E, boehlkei and E. okatie. Significant allele freq uency differences at a single nuclear gene locus corroborate the distinctiv eness of these ESUs, Phylogenies based on control region haplotypes and fre quencies of nuclear alleles are inconsistent with the currently described r ange of E. boehlkei and E. okatie, Despite inconsistency with described spe cies boundaries, the result of this genetic analysis for rare species manag ement is clear: conservation strategies that describe distinct population s egments inhabiting individual river systems should be encouraged.