RESUMEN
An eco-monitoring programme to assess faunal biodiversity in the main rivers of the northern Iberian Peninsula (Spain) reveals the first occurrence of the marbled crayfish Procambarus virginalis (Decapoda: Cambaridae) in Iberian inland waters. Iberian specimens have been identified by combining morphological and genetic traits. We discuss the most plausible pathways and introduction vectors, its potential invasiveness and subsequent impacts on host localities. Our preliminary results raise concern about the potential threat of P. virginalis to native fauna and ecosystem dynamics, as P. virginalis was found in an area of great cultural and ecological importance with relevant populations of endangered species. Due to the invasive history of the marbled crayfish, eradication of these individuals is urgent. This study confirms the importance of early warning systems for exotic species, keeping the population, forest guards and field technicians informed about potential invasive species to execute a rapid and effective response.
