Trophic flexibility and opportunism in pike Esox lucius.
The first comprehensive investigation of pike Esox lucius trophic ecology in a region (Ireland) where they have long been thought to be a non-native species is presented. Diet was investigated across habitat types (lake, river and canal) through the combined methods of stable-isotope and stomach content analyses. Variations in niche size, specialization and the timing of the ontogenetic dietary switch were examined, revealing pronounced opportunism and feeding plasticity in E. lucius, along with a high occurrence of invertivory (up to 60 cm fork length, LF ) and a concomitant delayed switch to piscivory. Furthermore, E. lucius were found to primarily prey upon the highly available non-native roach Rutilus rutilus, which may alleviate predation pressure on brown trout Salmo trutta, highlighting the complexity of dynamic systems and the essential role of research in informing effective management.
School of Biology & Environmental Science, University College Dublin, Belfield, Ireland.
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D
Pedreschi
School of Biology & Environmental Science, University College Dublin, Belfield, Ireland.|School of Environment & Life Sciences, University of Salford, Salford, M5 4WT, U.K.
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S
Mariani
School of Biology & Environmental Science, University College Dublin, Belfield, Ireland.
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J
Coughlan
Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
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CC
Voigt
Inland Fisheries Ireland, 3044 Lake Drive, Citywest Business Campus, Dublin, D24 Y265, Ireland.
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M
O'Grady
Inland Fisheries Ireland, 3044 Lake Drive, Citywest Business Campus, Dublin, D24 Y265, Ireland.
J
J
Caffrey
School of Biology & Environmental Science, University College Dublin, Belfield, Ireland.
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M
Kelly-Quinn
D000818:Animals; D004032:Diet; D017753:Ecosystem; D017859:Esocidae / Q000502:physiology*; D005247:Feeding Behavior; D005766:Gastrointestinal Contents; D007494:Ireland; D060106:Lakes; D011157:Population Dynamics; D011235:Predatory Behavior; D045483:Rivers
diet; freshwater fish; ontogenetic switch; predation; stable isotopes; trophic ecology