Geographical patterns in the body-size structure of European lake fish assemblages along abiotic and biotic gradients

• Main Authors: Emmrich, Matthias, Pédron, Sthépanie, Brucet Balmaña, Sandra, Winfield, Ian J., Jeppesen, Erik, Volta, Pietro, Argillier, Christine, Lauridsen, Torben L., Holmgren, Kerstin, Hesthagen, Trygve, Mehner, Thomas
• Other Authors: Universitat de Vic. Escola Politècnica Superior
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Biologia; Fennoscandian; Tundra
• Online Access: http://hdl.handle.net/10854/3666; https://doi.org/ 10.1111/jbi.12366

Aim Our aim was to document geographical patterns of variation in the body-size structure of European lake fish assemblages along abiotic gradients, and any differences in fish assemblage structure. We hypothesized that patterns in the body-size structure of entire lake fish assemblages are primarily temperature driven and consistent with the dominant pattern of the temperature–size rule, which suggests a decrease in adult body size with increasing developmental temperature for many ectothermic species. Location 356 European lakes. Methods Variation in the body-size structure of fish assemblages was explored on a continental scale along gradients of temperature, morphometry, productivity and fish assemblage structure for 356 European lakes. The mean fish assemblage body-size and individual body-size distributions were selected as size metrics. Separate analyses were conducted for lakes located within five ecoregion subsets (Borealic Uplands/Tundra, FennoScandian Shield, Central Plains, Western Plains and Western Highlands) and for lakes with different functional fish classifications (cold-, cool- and warmwater fish assemblages). Results Geographical patterns of variation in the body-size structure of European lake fish assemblages could be clearly discerned along a temperature gradient for both the continental dataset (356 lakes) and the smaller geographical (ecoregion) subsets. We found systematic changes in fish assemblage body-size structure across temperature gradients in correspondence with the dominant thermal fish guild. The majority of the lakes, mainly located in the warmer European lowlands, were dominated by eurythermic cool- and warmwater fish assemblages, with smaller sized individuals characterized by linear individual body-size distributions. Lakes located in colder regions and dominated by stenothermic coldwater salmonids with larger sized individuals were characterized by unimodal or bimodal size distributions. The mean body size of cold-, cool- and warmwater fish assemblages changed uniformly ...