Suppression of invasive topmouth gudgeon Pseudorasbora parva by native pike Esox lucius in ponds

1. Asian topmouth gudgeon Pseudorasbora parva has been recognized as a highly invasive cyprinid fish species in Europe that can present risk to native fish communities. 2. The present study aimed to investigate whether a native piscivorous fish, pike Esox lucius, is able to reduce the establishment success and invasiveness of topmouth gudgeon Pseudorasbora parva in shallow ponds. We performed a large scale, replicated whole-pond experiment in which ponds were spontaneously colonized by topmouth gudgeon and exposed to experimental native fish communities with and without pike. 3. Our results provide evidence for strong negative effects of pike stocking on the abundance and biomass of topmouth gudgeon, while we found no effects on native fish species. The present study suggests that the presence of native pike can considerably enhance the biotic resistance of fish communities against invasion by topmouth gudgeon. 4. We argue that the resistance of fish communities against invasion by exotic species may in some cases be enhanced by management strategies that reinforce the presence and abundance of naturally occurring and indigenous pike.status: publishe