“…The number of alien macroinvertebrate species in the Oder River is still growing. Altogether, at least 33 non-indigenous species have been so far identified in the Oder and in the Szczecin Lagoon (Gruszka, 1999;Szlauer-Łukaszewska and Grabowski, 2012;Jabłońska et al, 2015;Pabis et al, 2017;Szlauer-Łukaszewska et al, 2017;Jabłońska et al, 2018;Cebulska and Krodkiewska, 2019). Among them, nine amphipod species were identified: Chelicorophium curvispinum (Sars G.O., 1894), Dikerogammarus villosus (Sowinsky, 1894), D. haemobaphes (Eichwald, 1841), Echinogammarus trichiatus (Martynov, 1932), Melita nitida Smith, 1873, Obesogammarus crassus (Sars G.O., 1894), Pontogammarus robustoides (Sars, 1894), Gammarus tigrinus Sexton, 1939 and Cryptorchestia garbinii (Orchestia cavimana) Ruffo, Tarocco and Latella, 2014 (Konopacka et al, 2009;Rachalewski et al, 2013;Zettler and Zettler, 2017).…”