Genetic structure and connectedness of Southern Ocean pycnogonids (Chelicerata: Pycnogonida) in a changing environment

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Southern Ocean pycnogonids are abundant, diverse and highly endemic on an ocean basin scale. Despite some efforts in molecular evolutionary research on marine Antarctic invertebrates in recent years, the pycnogonids remain mostly unstudied. Hence, many questions concerning their evolutionary history remain and common zoogeographic hypotheses, e.g. the concept of circumpolar distribution, remain mostly untested. The aim of the proposed project is to analyse the genetic structure of pycnogonids with such a reported circumpolar distribution. Sequencing nuclear and mitochondrial genes, we first want to test whether the reported circumpolar distribution holds true or is just artifactual due to the presence of cryptic species. Second, for verified species, we aim at investigating the amount and direction of gene flow among populations using newly developed microsatellites and innovative bioinformatic approaches together with physical and biologcial oceanographic information on the Southern Ocean. In a third step, using the same DNA markers, we want to test whether shallow-water species on the Antarctic shelf have suffered more from past glaciation events compared to species with broad vertical distribution ranges since these may have escaped to the deep sea. In view of ongoing and upcoming environmental changes in the Southern Ocean as a result of a fast changing climate, our analyses of today’s intra- and interspecific genetic diversity of Antarctic Pycnogonida represent important baseline research for monitoring the response of Antarctic biota to changing conditions.