Patterns of diet overlap between populations of non-indigenous and native fishes in shallow ponds

摘要: No significant differences in the diet composition were detected for any of populations four non-indigenous fish species (brown bullhead Ameiurus nebulosus, pumpkinseed Lepomis gibbosus, topmouth gudgeon Pseudorasbora parva and eastern mudminnow Umbra pygmaea) two native (gudgeon Gobio gobio roach Rutilus rutilus), between small shallow ponds habitats within ponds, during late summer. Based on composition, groups size classes (’functional groups‘) distinguished. For most functional group combinations exotic fishes, overlap values low. Although chironomid larvae formed important food source, differential consumption allowed an degree niche differentiation fishes. In contrast, high was found indigenous several indicating a potential interspecific exploitative competition. The consisted almost entirely non-animal remains (detritus plant material). proportion such low-energy this may be indicative competition induced shift to suboptimal sources.