Stable isotopes and gut contents indicate differential resource use by coexisting asp (Leuciscus aspius) and pikeperch (Sander lucioperca)

0494915 - BC 2019 RIV DK eng J - Journal Article
Vašek, Mojmír - Eloranta, A. P. - Vejříková, Ivana - Blabolil, Petr - Říha, Milan - Jůza, Tomáš - Šmejkal, Marek - Matěna, Josef - Kubečka, Jan - Peterka, Jiří
Stable isotopes and gut contents indicate differential resource use by coexisting asp (Leuciscus aspius) and pikeperch (Sander lucioperca).
Ecology of Freshwater Fish. Roč. 27, č. 4 (2018), s. 1054-1065. ISSN 0906-6691. E-ISSN 1600-0633
R&D Projects: GA MŠMT(CZ) 7F14316; GA ČR(CZ) GA15-01625S
EU Projects: European Commission(XE) 677039 - ClimeFish
Institutional support: RVO:60077344
Keywords : dietary ontogeny * foraging strategy * interspecific competition * piscivory * stable isotopes
OECD category: Zoology
Impact factor: 1.742, year: 2018

Differential use of habitat and prey resources is an important mechanism that may allow coexistence of sympatric species. Unlike interactions between smaller cyprinid and percid fishes, the resource use by coexisting predatory asp (Leuciscus aspius) and pikeperch (Sander lucioperca) is relatively unknown. Here, gut content and stable isotope analyses were used to study ontogenetic dietary shifts and interspecific trophic niche overlap between asp and pikeperch coexisting in two reservoirs. The hypothesis that both species show an ontogenetic dietary shift from small invertebrates to large fish prey, but at the same time use different prey resources to reduce potential competitive interactions, was validated. The isotopic niches of the two predators showed no, or only a moderate, degree of overlap (0%-65%). The ontogenetic changes in the degree of interspecific isotopic niche overlap were different in the two reservoirs, suggesting that trophic segregation can be dynamic and variable among systems. Gut contents revealed that small (<100mm standard length) asp consumed mostly terrestrial invertebrates and emerged aquatic insects, whereas small pikeperch foraged on zooplankton, larval and pupal stages of aquatic insects and fish. Larger individuals (>100mm) of both species were predominantly piscivorous, with asp consuming more cyprinid prey and pikeperch more percid prey. Coexisting asp and pikeperch populations are able to utilise different prey resources, thereby reducing potential negative competitive interactions.
Permanent Link: http://hdl.handle.net/11104/0288134