A1 Journal article (refereed)
The crayfish distribution, feeding plasticity, seasonal isotopic variation and trophic role across ontogeny and habitat in a canyon-shaped reservoir (2020)
Veselý, L., Ercoli, F., Ruokonen, T. J., Bláha, M., Kubec, J., Buřič, M., Hämäläinen, H., & Kouba, A. (2020). The crayfish distribution, feeding plasticity, seasonal isotopic variation and trophic role across ontogeny and habitat in a canyon-shaped reservoir. Aquatic Ecology, 54(4), 1169-1183. https://doi.org/10.1007/s10452-020-09801-w
JYU authors or editors
Publication details
All authors or editors: Veselý, Lukáš; Ercoli, Fabio; Ruokonen, Timo J.; Bláha, Martin; Kubec, Jan; Buřič, Miloš; Hämäläinen, Heikki; Kouba, Antonín
Journal or series: Aquatic Ecology
ISSN: 1386-2588
eISSN: 1573-5125
Publication year: 2020
Publication date: 26/10/2020
Volume: 54
Issue number: 4
Pages range: 1169-1183
Publisher: Springer
Publication country: Netherlands
Publication language: English
DOI: https://doi.org/10.1007/s10452-020-09801-w
Publication open access: Not open
Publication channel open access:
Abstract
Man-made reservoirs are important freshwater ecosystems as they are globally common and share features of both standing and running waters. In streams and lakes, crayfish are an important component of freshwater ecosystems due to their habitat-modifying behaviour, substantial size, omnivorous feeding and often high abundance; however, their trophic role in reservoirs is not known. We evaluated the distribution and diet of noble crayfish (Astacus astacus) in the canyon-shaped, oligotrophic Nýrsko reservoir in West Bohemia region, Czech Republic. Using stable isotope analysis, we quantified the trophic level of all major components of the reservoir food web and investigated seasonal isotopic variation and how the trophic role of noble crayfish varied with habitat and ontogeny. Crayfish were an important food source for both predatory and omnivorous fish and consumed food sources from multiple trophic levels, including detritus, algae, zoobenthos and other crayfish. Throughout ontogeny, crayfish had similar levels of carnivory, but cannibalism was more prevalent in adult crayfish, while juveniles and sub-adults fed more on other zoobenthos. Moreover, crayfish had high feeding plasticity in time, as the relative importance of dominant food sources varied with season. Their feeding plasticity was especially evident in crayfish populations from different habitats, which adapted their feeding strategy to local resources. In addition, pelagic source usage increased with the depth as detritus and algae usage decreased. Proportion of females increased with the depth, while population density showed a unimodal response to the depth gradient. These findings indicate that crayfish are indeed ecologically important species with both direct and indirect roles in the trophic web of this reservoir ecosystem.
Keywords: aquatic ecosystems; food webs; reservoirs; Astacus astacus; isotope analysis; habitat; seasons
Free keywords: stable isotopes; reservoir; trophic chain; depth distribution; season; habitat; astacus astacus
Contributing organizations
Ministry reporting: Yes
Reporting Year: 2020
JUFO rating: 1