Abstract
The present paper summarizes all available scientific data on the historical and current occurrence of the endangered cyprinid fish species lake minnow, Eupallasella percnurus (Pall.), in Wielkopolskie Voivodeship in Poland. In the twentieth century, only three or four sites were identified in this part of the country. Today, there is only one site in the voivodeship situated in the vicinity of Wolsztyn, which is classified as highly threatened and is subject to protection under the European Ecological Natura 2000 Network as PLH300028 "Barłożnia Wolsztyńska". Although some findings of unknown sites of E. percnurus in Wielkopolska remain feasible, the prerequisite for the preservation of this species in this region is the urgent implementation of active protection measures. These should include an assessment of the present condition of the existing population, a partial deepening of the water bodies inhabited by this species, and searches for other water bodies nearby that are suitable for future introductions of wild or cultivated individuals in order to increase the number of existing populations.