A population genomic analyses of the recently radiated species flock of a free-living dinoflagellate. The sibling species occupy freshwater, brackish, and marine habitats, and co-occur in the ancient Lake Baikal. The species differ morphologically and in habitat-choice, but cannot be distinguished using traditional rDNA markers. Population genetic analyses will be performed to analyze population divergence, extent and direction of gene flow, and to determine potential loci under selection. THe RADtag sequencing method will be used to call and identify SNPs. The study is funded by VR.