Diet and Feeding Strategy of Northern Pike (Esox Lucius L., 1758) İnhabiting A Deep Dam Lake in Central Anatolia, Türkiye

Abstract

The aim of this study was to evaluate the seasonal diet composition and feeding strategies of northern pike (Esox lucius) located in Sıddıklı Küçükboğaz Dam Lake (Kırşehir, Türkiye). Monthly sampling from September 2015 to August 2016 resulted in the collection of 133 northern pike individuals, with their total lengths ranging from 23.4 to 86.6 cm (mean length 53.84 ± 10.51 cm). Stomach content analyses and stati stical tests, including a Kruskal-Wallis analysis, were employed to assess the seasonal variation in feeding intensity. Although numerical differences in the feeding intensity were observed, with the highest values recorded in summer (FI = 1.59) and the lowest in winter (FI = 0.51), these differences were not statistically significant (K-W test, p < 0.05). Among the physicochemical parameters of the surface water, tempera ture emerged as the primary environmental factor influencing the feeding patterns, based on the results of a Spearman’s rank correlation. The northern pike exhibited an exclusively piscivorous diet, primarily consuming Tinca tinca (44.83% by number and 56.16% by frequency of occurrence) as well as Atherina boyeri. Despite the availability of multiple prey species within the habitat, the northern pike demonstrated a strong prey specialisation toward these two fish species throughout the year. The observed consistency in this dietary preference underscores the species’ role as a specialised top predator and provides critical ecological insights for the management and conservation of similar freshwater reservoir ecosystems.