Prey selectivity in pike (Esox lucius), zander (Sander lucioperca) and perch (Perca fluviatilis) under experimental conditions

Prey selectivity in three important carp-pond predatory fish species - pike (Esox lucius), zander (Sander lucioperca) and perch (Perca fluviatilis) was examined under experimental laboratory conditions. Prey fish (39 - 53, 24 - 37 and 37 51% Tl of pike, zander and perch respectively) were submitted to predators originating from a pond culture. No particular selectivity was found in pike (139 3 mm Tl) which slightly preferred asp (Aspius aspius) fingerlings over chub (Leuciscus cephalus) and topmouth gudgeon (Pseudorasbora parva). The specific growth rate (SCR) and food conversion ratio (FCR) in pike fed live food were 1.09 +/- 0.25 % day(-1) and 6.93 +/- 1.07 g g(-1), respectively. Only chub and roach (Rutilus rutilus) fingerlings were preferred by zander (244 13 mm Tl) while other prey fish like perch, topmouth gudgeon and asp were avoided. The SGR and FCR values in zander fed live fish under experimental conditions were 1.67 +/- 0.14% day(-1) and 3.41 +/- 0.49 g g(-1) respectively. Perch (148 +/- 2 mm Tl) preferred only topmouth gudgeon and avoided asp and chub fingerlings. Thus, the SGR and FCR values for perch were assessed as 1.07 +/- 0.13% day(-1) and 6.55 +/- 0.35 g g(-1), respectively.