In the present study, we assessed ecological and historical factors (Gondwanan vicariance, marine dispersion) and potential dispersion (niche-tracking) that explain distribution of Galaxias maculatus in the Southern Hemisphere based on occurrences available in the Global Biodiversity Information Facility (GBIF; period 1980 to 2022) and ichthyological sampling in five river systems in southern Chile between March and November 2019. Ocurrence data extracted from GBIF are available at http://www.gbif.org and additional ichthyological sampling data that were used are provided here. Data provided here are based on sampling of Galaxias maculatus at 12 sites in five river systems in southern Chile during March, May, August, and November 2019. Sampling sites were selected to cover a continuous river gradient, including (whenever possible) the lower, middle, and upper sections of each river system. Fish were captured using beach seines (5 m long, 1.5 m high, and 10 mm stretched mesh) in shoreline habitats of each evaluated river system.

Occurrences of Galaxias maculatus obtained from ichthyological sampling in five river systems in southern Chile between March and November 2019 with corresponding geographic coordinates (decimal degrees WGS84).