Map showing the marbled crayfish Procambarus fallax f. virginalis occurrence in Bratislava, Slovakia – general view (A) and detailed location (B). Asterisk refers to the pumping station, while 1 and 2 to the locations in the Chorvátske rameno canal and the Jarovecke rameno side arm where marbled crayfish and spiny-cheek crayfish Orconectes limosus were found, respectively. Fecundity of marbled crayfish females (C) expressed as the number of eggs (circles), stage 1 (triangles) and stage 2 juveniles (squares), respectively, and the relationship between female carapace size and the number of offspring (exponential regression, with all three age categories pooled). The basis for the maps is available under the Open Database License (www.openstreetmap.org).