Evolution of the French ichtyological communities and conservation strategies

France has always enjoyed a rich ichthyological history, with major changes in populations, especially in the last two hundred years. As it stands, Fr ance's current freshwater fish communities is the result of many past and p resent phenomena still taking place within various time scales. Studying th e changes from the late Tertiary to the current period is essential if one is to conserve and manage this ichthyofauna. For example, many problems, or even conflicts, resulting from species intro ductions can take on a different character when the specificity and the his tory of the catchment area concerned are taken into account. This work investigates therefore what contribution studies in biogeography, palaeontology, archaeoichthyology, ecology and history can make towards a better understanding of the evolution of fish communities in France. It focuses first on Tertiary fossils and fish remains from the Quaternary, setting those in a European and national context, followed by a study on an cient and current distributions of the various species, using specific tool s. This work puts forward certain reference communities for the main catchment areas in France thus defining a reference state and making it possible to compare the current state of species distribution with this reference state , in order to measure the impact of natural and anthropogenic factors on th e changes in communities in the last 5000 years. Taking these changes in distributions and populations into account, this wo rk draws up the list of threatened species and puts forward conservation me asures based on their ecology, while suggesting action plans for each speci es; it also analyses the part played by the protected area in the conservat ion of the ichthyofauna.