Project R-3965

Are small animal species indeed everywhere?: a case study. (Research)

In contrast to distribution patterns of large animals, small animals (less then 2 mm) are often said to have a wide, even cosmopolitan distribution. This view, pronounced as the "Everything small is everywhere" theory, has often been questioned, and in many cases seems to be the result of problematic species delimitation. This is not different for small free-living flatworms, which occur in high numbers in all wet habitats. As a case study of the biogeography of microturbellarians, this project focuses on the freshwater genus Gieysztoria, many species of which are said to be widely spread. Using mitochondrial and nuclear genetic markers, it will first be explored how species within this genus can be delineated. After that, a phylogeographical analysis of the genus will be performed, in order to investigate whether specific biogeographical patterns can be retrieved. Moreover, a thorough study on the morphology of the genital organs and especially the stylet will be carried out, as this forms the basis to identify species and species groups in traditional taxonomy. An integrative approach using molecular and morphological data in combined phylogenetic analyses (ancestral state reconstruction) will provide more insight in the evolutionary role of the reproductive structures. Finally, divergence times will be estimated within this genus using species collected from volcanic islands and ancient lakes of which the geological origin is known as calibration points

16 February 2013 - 15 February 2017