Systematic revision and phylogeny of the Polygordiidae Czerniavsky, 1881 (Annelida: Polychaeta) based on morphological and molecular methods

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The proposed research aims at a systematic revision and an analysis of the phylogeny of the Polygordiidae, an ecologically and evolutionarily important polychaete group. Species of Polygordius are among the most abundant members of macrofaunal communities in coarse sand habitats and likely have a major impact on sediment chemistry as they occupy the interstices of sandy sediments and are highly motile. Despite this and several observations suggesting that some species may be particularly susceptible to short and long-term environmental changes this group is often missed or left unidentified in environmental surveys due to lack of available identification keys and defining polychaete characters. As morphological characters examined to date have been of limited diagnostic value for the distinction among Polygordius species some of the so-called cosmopolitan species may actually be comprised of several cryptic species and preliminary research suggests that species diversity within this group is largely underestimated. In the proposed project the status of all species currently known in this taxon will be clarified and species new to science will be described thus redefining the diversity of the taxon for the first time since its erection in 1881. For better distinction among species and understanding of the phylogeny, evolution and biogeography of the group we propose an integrative approach using molecular and morphological methods, i.e. DNA-sequencing and LM, SEM, TEM, and cLSM. Our results will be applicable to future research including further phylogenetic and cladistic analyses of polychaete systematics, and to the identification of species collected in environmental impact surveys. An up-to-date identification key to the Polygordiidae and a barcode for those species investigated will be produced. In addition to publications and presentations, data resulting from this research will be submitted to various web-based databases that are linked to major information systems for biodiversity and biogeography. Reference DNA-samples will be deposited in suitable collections for long-term storage and availability. A review of the results of the proposed research will be contributed to the new edition of the “Handbook of Zoology.