Mitochondrial DNA Sequencing Reveals Extreme Genetic Differentiation in a Cryptic Species Complex of Neotropical Pseudoscorpions

Abstract

The neotropical pseudoscorpionCordylochernes scorpioides(Chernetidae: Lamprochernetinae) is currently described as a single species ranging from Central America to northern Argentina. However, interpopulation crosses have recently demonstrated thatC. scorpioidesactually represents a complex of cryptic species. Here we present mitochondrial COI gene sequence data fromC. scorpioidesindividuals from Panama, Trinidad, and French Guiana which demonstrate little or no intrapopulation variability but divergence ranging from 2.6 to 13.8% between geographic populations. Phylogenetic analysis provides evidence of a major split betweenC. scorpioideslineages from Central and South America. Levels of interpopulation mtDNA divergence correspond well with previously established patterns of postzygotic reproductive incompatibility between geographically distinct units within theC. scorpioidescomplex. By contrast, multivariate morphometric analysis demonstrates that extensive sequence divergence has occurred in the absence of appreciable morphological differentiation between the populations. To provide a framework for assessing the scale of geographic divergence inC. scorpioides, Cordylochernessequences were compared with homologous sequence from its presumed sister taxon,Lustrochernes,and fromParachernesandSemeiochernes,representatives of the second chernetid subfamily, the Chernetinae. Our preliminary, generic-level analysis suggests that COI sequence data may prove useful in resolving relationships within this problematic family.