Selectivity of Pikeperch Sander lucioperca (Percidae, Perciformes) Larvae when Feeding on Lake Zooplankton under Culture Conditions

The feeding selectivity of pikeperch Sander lucioperca (Linnaeus, 1758) larvae was studied in early ontogenesis (from 3 to 21 days after hatching) under culture conditions when feeding with zooplankton from Lake Sukhodolskoye (pikeperch natural habitat). The cladocerans Bosmina longirostris (O.F. Müller, 1776) and Polyphemus pediculus (Linnaeus, 1758) (up to 80–100% of food objects in the food bolus), the most abundant species in the lake (92.92–99.57% of the number of zooplankters), formed a basis of the diet of pikeperch larvae in the first 15 days. At the initial stages of life of the pikeperch larvae, the portion of food objects suitable in sizes for their feeding reached 8.7%. The portion of zooplankters that the larvae preferred for feeding was also low (18%). Apparently, this negatively affected the survival rate of juveniles (∼30% in the first week and 3.6% at the end of the study), as well as significant variability in larval size (coefficient of variation in juvenile weight 72%) and cannibalism.