Biogeography at the Sundaland-Wallacea interface: testing hypotheses with freshwater shrimps

The Sunda shelf area, also called Sundaland, and the Wallacea, a region of oceanic islands between two continental shelves, are hotspots of biodiversity. Both are situated within a geologically very active region and are separated by deep-water channels. Their fauna has a complex biogeographical history, which remains insufficiently understood despite a long respective research record. The islands of Sundaland were repeatedly connected to mainland Asia during the Pleistocene, when the shelf was fully exposed at the glacial maxima, and their fauna resembles that of the SE Asian mainland. In contrast, the islands of the Wallacea never had such a land connection and its fauna is characteristically depauperate at a higher taxonomic level and largely endemic at the species level. Regardless of the proposed biogeographic boundaries between both regions, a preliminary study on the Indonesian island Sulawesi (Wallacea) indicated a vicariant scenario for the origin of its endemic freshwater shrimps from Asia (including Sundaland) quite in contrast to many current studies that emphasise dispersal for various groups. The freshwater shrimp genus Caridina, which pursues different reproductive strategies (poor vs. good dispersal potential), will be used as a model organism to study the colonization of different regions in Sundaland and Wallacea by true freshwater lineages and to test vicariant vs. dispersal hypotheses, particulary on Sulawesi and the Philippines, using a multi-marker molecular phylogeny and a molecular clock approach. The project will contribute towards a better understanding of the historical processes shaping the diversity and its distribution in the ancestral area of biogeography through a rigorous testing of biogeographic hypotheses.

Principal Investigators
Rintelen, Kristina von Dr. (Details) (Molecular Genetic)

Duration of Project
Start date: 08/2009
End date: 07/2012

Last updated on 2020-13-03 at 23:06