Non-native fish in Belarusian and Polish areas of the European central invasion corridor

This is the first comprehensive review to examine the role of the central European invasion corridor on fish introductions into Belarusian and Polish inland waters (Dnieper-Bug-Vistula-Oder-Elbe-Spree-Havel). Historical and recent data were assessed, including the results of a 2003–2008 survey along the Belarusian and Polish sections of the corridor. Since the eighteenth century, at least six fish species of Ponto-Caspian origin have spread via the corridor and migrated westwards to the Baltic basin, with five species found in recent surveys, namely the monkey goby Neogobius fluviatilis, round goby N. melanostomus, racer goby N. gymnotrachelus, tubenose goby Proterorhinus marmoratus and the white eye-bream Abramis sapa. Four other non-native species were also found within the corridor — the Amur sleeper Perccottus glenii, gibel carp Carassius gibelio, brown bullhead Ameiurus nebulosus and the topmouth gudgeon Pseudorasbora parva. Their presence is related to numerous accidental introductions to many localities in Belarus and Poland, rather than from using the corridor as an invasion route. One species, the ninespine stickleback, Pungitius pungitius, has migrated from the Baltic basin to the Black Sea drainage systems.