Using molecular genetic analysis to identify the population of invasive species and studying the biological problems they cause during the colonisation process.Invading species pose the second biggest threat to biodiversity, after loss of habitat, and are one of the main driving forces behind global changes.These problems especially affect continental waters (rivers, lagoons and reservoirs), one of the habitats where the invading species have a strong and economically significant ecological impact.On the other hand, the biological invasions represent unique opportunities for studying the evolutionary processes on a human time scale.Notable invading species studying in this area include the zebra mussel (Dreissena polymorpha), one of the invasive invertebrates with major ecological and economic impact, and the eastern mosquito fish (Gambusia holbrooki), an exotic continental fish introduced for fighting against mosquitoes in our lagoons.Both species are considered to be as among the world’s 100 most harmful invading species according to the GISP (Global Invasive Species Programme).These species, together with the Asian clam (Corbicula fluminea) are currently being studied by the group, based on projects in progress.