Galicia (NW Spain) has a dense river network constituted by small coastal rivers, which present a high number of freshwater endemics. However, in the last two decades there has been a steep increase on the records of freshwater invaders on the region, and these constitute an important threat for its freshwater biodiversity. Most of the exotic species present in Galicia have been previously recorded in other areas of the Iberian Peninsula. The temporal analysis of the evolution of the records of invasions in Galicia and in the rest of the Iberian peninsula, shows that the tendency adjust to a decreasing linear regression, with species introduced after 1995 in other Iberian areas being almost immediately present also in Galicia. Detailed analysis of pathways of introduction underlines the important role of aquarium trade on these results, which needs to be regulated if we want to stop or at least retard the introduction of new invasive species on freshwater habitats.
Invasive species; Freshwater; Galicia; Iberian Peninsula; Aquarium trade