The Phoxinus of all lakes and streams of the Aare system correspond to

P. csikii .

This extension of the previously known distribution range is complimentary to the data of Palandačić et al, filling the gap between the previous records in Bavaria and those in Lake Geneva that were previously appearing isolated.The new distribution range data is consistent with the expansion out of a Danubian refugium and into the Swiss midlands via the old postglacial Danubian connections of Lakes Walen and Constance that were subsequently captured by the Rhine catchment. P. csikii is hence, likely the native minnow of the Swiss Rhine and Aare catchments, possibly including Lake Geneva.