In total, we examined the digestive system of 635 pikeperch, 350 Eurasian perch Perca fluviatilis L., 265 ruffe Gymnocephalus cernuus
(L.), 13 roach Rutilus rutilus (L.), 20 common bream Abramis brama (L.), 10 vendace, and 21 smelt with a SL between 4 and 15 cm.
2011) were used for some prey species, which have never been caught in the reservoir or caught in very small numbers, such as weatherfish, Misgurnus fossilis; Chinese sleeper, Perccottus glenii; ruffe, Gymnocephalus cernuus
Less abundant commercial fish species represented were Northern pike, Esox lucius L.; burbot, Lota lota (L.); ruffe, Gymnocephalus cernuus
(L.); and Peipsi whitefish, Coregonus lavaretus maraenoides Poljakow.
predation pressure following the introduction of ruffe Gymnocephalus cernuus
(L.) to Loch Lomond.
Ecological interactions among the "exotic triad" Eurasian ruffe (Gymnocephalus cernuus
), round gobies (Neogobius melanostomus), and zebra mussels (Dreissena polymorpha), and their effects on native yellow perch (Percaflavescens).
The bioturbation produced by Gymnocephalus cernuus
(Linnaeus, 1758), a highly specialized detritivorous fish from a mesotrophic lake (Lake Pyhajarvi, southeastern Finland), feeding exclusively on chironomids and other invertebrates, significantly increased total phosphorus, dissolved [PO.sup.3-.sub.4], total nitrogen, [NH.sub.4]-N concentrations and water turbidity under experimental conditions (Taivainen et al., 2005).
A comparative study on the trophic relations of ruffe Gymnocephalus cernuus
(L.) and state of its populations in two large shallow lakes with different fish fauna and food resources.
Sequences from ruffe (Gymnocephalus cernuus
) and walleye (Sander vitreus) were used for outgroup comparison.
Latin name Gymnocephalus cernuus
, it has infested Loch Lomond since it was introduced by fishermen in the early 1980s.
Changes in abundance of two percids, Perca fluviatilis and Gymnocephalus cernuus
, along a productivity gradient: relations to feeding strategies and competitive abilities.
ruffe Gymnocephalus cernuus
) tend to be rather uncommon in reservoirs, their distribution and numbers depending on local geography or the physical characteristics of the system (Jeppesen et al.
* ruffe (Gymnocephalus cernuus
L.) from Tvarminne (H-Tva), Vaike Vain (VV), and Pargas-Parainen (PP);