Genetic divergence among populations of the Madison Cave isopod, Antrolana lira

The federally threatened Madison Cave Isopod, Antrolana lira , inhabits phreatic aquifers in the Shenandoah Valley of Virginia and West Virginia. In this study, I analyze a region of mtDNA coding for the COI from 70 individuals from nine locations. Analysis revealed three highly divergent lineages in separate geographic areas (uncorrected "p" = 0.095--0.112). Within these lineages genetic divergence is low (uncorrected "p" < 0.01). Lineages diverged between three and 21 mya. Over 99% of the genetic variation corresponds to among group variation. Nested Clade Analysis revealed restricted gene flow within the northern group. The Massanutten synclinorium and non-soluble rock likely contributes to genetic isolation, and several hypotheses about colonization are presented. The three haplogroups are Evolutionary Significant Units and should be represented in management plans.