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Research article - Peer-reviewed, 2019

Size-dependent diet composition and feeding of Eurasian perch (Perca fluviatilis) and northern pike (Esox lucius) in the Baltic Sea

Jacobson, Philip; Bergstrom, Ulf; Eklof, Johan


To understand food web dynamics, knowledge about factors influencing trophic interactions is fundamental. Using stomach content analysis, we investigated size-dependent predator-prey relations of two coastal predatory fish in the Baltic Sea: perch (Perca fluviatilis) and northern pike (Esox lucius). Perth undergo two ontogenetic diet shifts, from zooplankton to macroinvertebrates at ca. 50 mm; and then to fish at ca. 250 mm. For pike, all sizes (103-810 mm) fed almost exclusively on fish. The fish prey of perch and pike was predominantly three-spined stickleback in spring, and gobiids in late summer. The mean and maximum prey:predator size ratio was larger, while the minimum was smaller for pike compared with perch. Perch and pike fed on smaller-sized gobiids, three-spined and nine-spined stickleback compared within the environment. Our results on size-dependent diets of perch and pike is useful for quantitative analyses of food-web interactions and for ecosystem-based management.


Eurasian perch (Perca fluviatilis); Northern pike (Esox lucius); food web dynamics; trophic interactions; stomach content analysis; size-dependent diets

Published in

Boreal Environment Research
2019, volume: 24, pages: 137-153

Authors' information

Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Eklöf, Johan
Stockholm University

UKÄ Subject classification

Fish and Aquacultural Science

URI (permanent link to this page)