New data on distribution of the monkey goby, Neogobius fluviatilis (Pallas, 1814) in Bosnia and Herzegovina and Croatia with notes on ecology and associated fish fauna

The invasive fish species Neogobius fluviatilis was recorded at one locality on each of the two investigated rivers, Una and Kupa. The expansion of this species in Bosnia and Herzegovina is presented, as well as the habitat characteristics of the locality on the Una River. Additionally, a list of the associated fish fauna at both localities is given: 18 and 29 additional fish species were recorded for the Una and Kupa Rivers, respectively.