Dispersal Capabilities Do Not Parallel Ecology and Cryptic Speciation in European Cheliferidae Pseudoscorpions (Pseudoscorpiones: Cheliferidae)

Abstract

The ability to disperse has continually shaped both the distribution and diversification of biota, and it affects the survival of the species with respect to wide-ranging habitat loss. As a response, organisms unable to spread by their own means often developed surrogate dispersal strategies. Pseudoscorpions possess small body sizes and cannot actively disperse over large distances and geographic barriers; therefore, they have adopted other ecological strategies. They are either sedentary and remain confined to stable environments or passively disperse via phoresy and are capable of inhabiting a wide variety of habitats, including temporary ones. In this paper, we use barcoding data to investigate the genetic diversity of four widely distributed and relatively morphologically uniform Cheliferidae genera Chelifer, Dactylochelifer, Rhacochelifer and Hysterochelifer. We aim to (i) test whether the genera harbor cryptic diversity and (ii) evaluate whether the genetic structure of the species parallels their dispersal capabilities and habitat preferences (i.e., ecological strategies). In general, we uncovered independent lineages within all analyzed genera, which indicates their need for a thorough and integrative taxonomic revision. More specifically, we detected a varying degree of genetic structuring among the lineages. Known phoretic species, as well as some species and delimited lineages that are not known to use this manner of dispersal, showed a complete lack of geographical structure and shared haplotypes over large distances, while other taxa had restricted distributions. We argue that genetic structure can be used as a proxy to evaluate species' dispersal manner and efficacy. Our results also suggest that taxa inhabiting stable environments might use phoresy for their dispersal.