Population-specific DNA fingerprints in a neotropical pseudoscorpion (Cordylochernes

The pseudoscorpion, Cordylochernes scorpioides, is currently described as a single species, ranging throughout the rain forests of Central and South America. Populations from Panama and French Guiana appear morphologically and behaviourally indistinguishable. However, DNA fingerprinting, using the probe Ml3, revealed distinct, population-diagnostic clusters of low molecular weight bands (< kb). This appears to be the most extreme case of population differentiation in minisatellite DNA so far detected in outbred, sexually-reproducing populations. As the two populations also exhibit allozyme divergence and are reproductively incompatible at the postzygotic stage, we conclude that they are, in fact, cryptic species, the characteristics of which are apparent only at the molecular level.