Feeding biology of pike, Esox lucius L., 1758 inhabiting Lake Ladik, Turkey

Abstract

This study was conducted to determine feeding biology and prey selection of pike inhabiting Lake Ladik (Ladik, Samsun). Sampling was carried out monthly between November 2009 and October 2010. The stomachs of 204 individuals were analyzed and 32.35% of them were empty. Feeding intensity varied by seasons and length group. Fullness index values were the lowest during summer and in large sized pike, while feeding intensity was the highest during autumn and in small specimens. Prey fish dominated the diet in all length groups throughout the year whereas feeding on invertebrates was limited to small pikes. For small, medium and large length individuals, the most preferred prey fish were Perca fluviatilis (V-a = 0.139, chi(2)= 3.86, P < 0.05), Chondrostoma regium (V-a = 0.169, chi(2) = 5.752, P < 0.05) and Abramis brama (V-a = 0.337, chi(2) = 22.731, P < 0.01), respectively. The pike exhibited a specialist feeding strategy on fish. The most important food items of pike were Scardinius erythrophthalmus, Perca fluviatilis and Abramis brama, respectively. Also, it was determined that there were significant positive relationships between prey dimensions-predator size and predator mouth sizes-predator length.