Spatial distribution of exotic fish species in the Guadiana river basin, with two new records

Abstract

Spatial distribution of exotic fish species in the Guadiana river basin, with two new records This work updates the spatial distribution of the exotic fish species in the Guadiana river basin. To this effect, 241 river stretches and 37 reservoirs and lakes were sampled, corresponding to 261 UTM 10 × 10 Km squares. A total of 12 exotic species were found, including two new species that had not been previously cited in the area, the channel cat-fish (Ictalurus punctatus) and the roach (Rutilus rutilus). These two species, related to lentic systems, had a very restricted distribution in the basin, probably as a consequence of its recent introduction. The expansion of the remaining exotic species was also confirmed. Some species as the pumpkinseed sunfish (Lepomis gibbosus), the mosquitofish (Gambusia holbrooki) or the largemouth bass (Micropterus salmoides) have become common components of the fish community, not only in reservoirs but also in lotic systems.