Potencjał wzrostowy larw trawianki Perccottus glenii Dyb. w warunkach kontrolowanych - implikacje dla rodzimych gatunków ryb

The invasive fish species the Amur sleeper, Perccottus glenii, has expanded rapidly its range of occurrence, and is reported in increasing numbers of European countries, including Poland. It is also considered dangerous to native ichthyofauna everywhere. Knowledge of its biology remains meager, especially with regard to the larval and early juvenile life stages. The aim of the current experiment was to evaluate the growth potential of Amur sleeper larvae using standard feeding tests performed under laboratory conditions. The results obtained were compared with corresponding data on some common, co-existing, freshwater fish species. The results provided evidence that the larval Amur sleeper growth rate is lower than that in species such as tench, rudd, chub, and perch. However, it was clearly higher than those of crucian carp and lake minnow, which is critically endangered in Poland These two species are increasingly accompanied by the invasive Amur sleeper in their natural habitats. In light of the Amur sleeper larval growth rate, high activity level, feeding plasticity immediately following hatching, and similar spawning period to many phytophilous cyprinids, it can be concluded that this alien species is capable of eliminating some native fish species by preying on eggs and larvae during the first weeks after hatching.