The diet of Eurasian perch larvae in lakes with different zooplankton assemblages

Eurasian perch has a great ecological importance in freshwaters as it is often a dominating predatory fish in ecosystems. The knowledge of perch feeding patterns, strategies, and adaptivity to food environment in their early life stages is essential to understand its population development and dynamics. It has been demonstrated that there exists a positive relationships between preferred prey availability and larval feeding success. We examined the diet of larval perch in their natural habitats of different zooplankton assemblages in three small lakes with varying ecological status. In each lake, both pelagial and littoral were studied. We found significant relation between zooplankton biomass in the lake and zooplankton biomass consumed by fish larvae. The most important food objects were crustaceans (Bosmina longirostris, Chydorus sphaericus). Ciliates were consumed only in one lake. Our results show that perch larvae are flexible in their choice of food and can adapt to different food environments.