Replication data for \"Urbanization can increase the invasive potential of alien species\"

This dataset was used to investigate whether the success of urban invaders is related to changes in species traits that enhance invasive potential. It was also used to explore whether a trophic mechanism helps explain the success of invaders in urban systems. All data come from one single model species, the guppy, Poecilia reticulata, which occurs in both urban and non-urban aquatic systems worldwide. This study took place in Rio de Janeiro, Brazil, where guppies have invaded many brackish and freshwater systems. We selected 6 urban stream reaches and 6 non-urban stream reaches, with the selection of urban streams based on the presence of development and evident direct sewage input, while non-urban streams were located inside parks and forest reserves. Within each treatment (urban, non-urban), 3 reaches had guppies as the only fish (guppy only), while in the other 3 guppies co-occurred with potential competitors and predators (guppy and other fish species). Whenever possible we sampled each reach in two years (2016-2017).