Diet, stable isotopes and morphology of Eurasian perch (Perca fluviatilis) in littoral and pelagic habitats in the northern Baltic Proper

• Published in: Environmental biology of fishes Vol. 97; no. 6; pp. 675 - 689
• Main Authors: Mustamäki, N, Cederberg, T, Mattila, J
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.06.2014; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal Systematics/Taxonomy/Biogeography; Animal, plant and microbial ecology; Animals; Aquatic habitats; Autoecology; Biological and medical sciences; Biomedical and Life Sciences; Brackish; Brackish water; Brackish water ecosystems; Diet; Environment; Fish; food choices; Freshwater & Marine Ecology; Freshwater environments; Fundamental and applied biological sciences. Psychology; General aspects; Habitats; Isotopes; Life Sciences; Nature Conservation; Perca fluviatilis; perch; Stable isotopes; stomach; Synecology; Vertebrata; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Zoology; Baltic Sea; Baltic states; ANE, Baltic Proper; ANE, Baltic Sea; Resource polymorphism; Body depth; Stomach contents; Brackish water; Individual specialisation; Brackish water environment; Environmental factor; Depth; Pelagic zone; Feeding; Freshwater environment; Vertebrata; Diet; Morphology; Perca fluviatilis; Pisces; Habitat; Teleostei; Isotopes; Osteichthyes; Polymorphism
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-013-0169-8

We present morphology, stable isotope signals and stomach contents of Eurasian perch (Perca fluviatilis) from littoral and pelagic habitats in a brackish water embayment in the northern Baltic Proper. Studies conducted in freshwater habitats repeatedly state that littoral perch have deeper bodies than the pelagic ones. In this study we observed the opposite; the perch from the pelagic study site had deeper bodies than the littoral ones, indicating that more factors than habitat structure affect the perch morphology. A possible explanation to this discrepancy is the diet choice; the pelagic perch in this study were more benthivorous than freshwater pelagic perch. Our results on stable isotope signals combined with the stomach contents also shed new light on the dietary preferences of perch. Perch is known to be a generalist predatory fish, but our results indicate that perch have individual diet preferences. Based on our results, it seems that at some point in their lives the perch in brackish water choose between the littoral and pelagic habitats and also specialise in a certain diet. This study shows that the perch morphology and diet in the Baltic Sea coast differ among habitats, but the patterns are not similar to those observed in freshwater studies.