The introduction of Perccottus glenii in the Latorica river in Eastern Slovakia before 1998 which expanded its range within 5 years to include Bodrog and Tisza together with aquatic habitats in their floodplains has resulted in the decrease in populations of Carassius carassius which were abundant in the past through competition for identical habitat requirements. Also Ref. 1739, 52537.

Status of threat: endangered (Ref. 90058).