This project aims at a study of intra- en interpopulational genetic diversification of the active and passive (resting stages) component of natural populations of Branchiopoda. The integration of stochastic (dispersion, colonisation) and ecological-genetic (outbreeding depression, selection) processes, and taking into account the different impact of sexual reproduction in the taxonomic groups studied, we will obtain a better insight into the processes that lead to local genetic differentiation of natural zooplankton populations, and the mechanisms that maintain this local genetic differentiation.