Diet Composition and Reproductive Properties of European Conger, Conger conger (Congridae) in the Turkish Aegean Sea

The diet composition and reproductive properties of European conger, Conger conger (Linnaeus, 1758) were investigated from the Aegean Sea of Türkiye to compare our data with those from other regions of the Mediterranean Sea and throughout all four seasons. A total of 100 individuals were examined. Totally 19 prey taxa belonging to three large taxon (cephalopods, crustaceans, and fishes) were identified in the stomachs of European conger. According to the relative significance index the crustaceans were dominant food in diet of individuals smaller than 50 cm, while fish prevailed in diet of fish with length between 75 and 100 cm. Histological analysis of 80 gonads showed that all individuals were immature (20%) and maturuing females (80%). Maturing females were with oocytes in the previtellogenic (16% of all fishes) and early vitellogenic phases (64%). The oocyte diameters were 80–476 μm at previtellogenic (diameter range 80–240 μm) and 245–476 μm at early vitellogenic individuals. Immature females had the gonads with the oocyte diameter < 30 μm