The effect of ontogenetic diet shifts on sagittal otolith shape of European perch, Perca fluviatilis (Actinopterygii: Percidae) from Lake Ladik, Turkey

European perch undergoes several ontogenetic dietary shifts during its lifetime. The present study focused on the variability in otolith shape caused by changes this species. A total of 172 specimens (7.5 to 27.5 cm TL) were caught local fishermen Lake Ladik from April November 2019. Shape indices (SIs) and elliptic Fourier coefficients (EFCs) calculated for each otolith. To detect shape, SIs EFCs compared among three defined size classes (I, II, III). Size-related groups distinguished both EFCs. Otolith analysis was more effective than morphometric distinguishing groups. Simultaneous use methods improved classification success method alone. This demonstrated that is influenced diet. However, sexual maturity fish also responsible these variations shape.