In the present study, we faced a situation in which the presence of
invasive species and the subsequent hybridization with commercially
important fish species may represent a serious problem for fish farming.
Common carp (Cyprinus carpio) as a commercially important fish species representing one of the most frequently consumed fish species in
the Czech Republic and several other central European countries is
reared extensively in traditional breeding ponds. Recently, the presence
of invasive gibel carp (Carassius gibelio) in such breeding ponds has
been observed, this results from human activity – young gibel carp are
introduced accidentally into some ponds with young common carp
and then, gibel carp enters through connecting channels to the other
ponds within the pond system (Vetešník, pers. com.). Gibel carp forms
a diploid-polyploid complex with two co-occurring reproductive
forms, sexual and gynogenetic. The successful invasion of this species
into novel habitats is linked with gynogenesis, i.e. asexual reproduction
in which offspring are formed parthenogenetically but the development
of eggs is induced by sperm of the same or phylogenetically closelyrelated sexually reproducing species. The rapid reproduction achieved