Construction of a barcode reference library of Dutch freshwater zooplankton

Water fleas (Cladocera) form a species rich group that play an important ecological role in freshwater ecosystems, such as ponds, lakes, ditches, canals and pools. Biodiversity research on this group is hampered because of the highly specialized taxonomic expertise and large time investments required for the analysis of samples. However, the rapid development of next generation sequencing (NGS) techniques creates the prospect of automatizing the identification of species in community samples through bulk DNA sequence analysis (metabarcoding). To be reliable and successful, such approach requires an extensive and curated library of regionally acquired barcodes. Unfortunately, West-European populations of cladoceran species are not or only very poorly represented in publicly available databases (e.g. Boldv4, NCBI). The aim of this project therefore is to establish a high-quality, curated reference library for the marker gene COI (cytochrome c oxidase I) of all cladoceran species in The Netherlands. For this, a large variety of freshwater habitats are being sampled across The Netherlands. Cladocerans retrieved from these samples are identified individually by Martin Soesbergen (Rijkswaterstaat), an expert in Cladoceran taxonomy, after which their COI gene is sequenced at NIOO-KNAW. The resulting reference library will strongly facilitate end users to identify unknown specimens and contribute to the detection of cryptic diversity. Together with a bioinformatics pipeline, also assembled at NIOO-KNAW, this library will strongly enhance our ability to monitor and survey zooplankton communities in The Netherlands.