Intraspecific spatial genetic differentiation of a Daphnia species within a long narrow reservoir

摘要: Environmental gradients influence the distribution and taxonomic composition of planktonic taxa, including Daphnia. In canyon-shaped reservoirs with pronounced horizontal food supply, predation pressure other factors, not only species interspecific hybrids but also clones within these taxa are non-randomly distributed. Using a long-term data set from reservoir mostly dominated by single Daphnia species, we evaluated whether intraspecific genetic differentiation can be frequently detected between upstream downstream regions different environmental conditions. We analysed variation at four allozyme loci (two species-specific two polymorphic) to assess collected in years (between 1995 2005) periods growing season. D. galeata all samples, although were occasionally detected. Despite limited loci, significantly genetically differentiated on seven out twelve sampling dates. Although drift geographically distant subpopulations may contribute differentiation, presume that observed patterns primarily due selection regimes. predict significant populations occurs more natural water bodies.