A comparative study on the feeding of eel, Anguilla anguilla (L.), bream, Abramis brama (L.) and ruffe, Gymnocephalus cernuus (L.) in Lake Võrtsjärv, Estonia

Morphological and histochemical study of intestine in wild and reared European eel (Anguilla anguilla L.)

“…WE is a carnivorous fish, which eats various kinds of fish, mollusks and other invertebrate animals (De Nie 1987;Lammens et al 1985;Kangur et al 1999) having a higher level of lipids and protein in its diet. High content of protein and lipid in RE diet is probably responsible for the higher activity of esterase, acid phosphatase and aminopeptidase, enzymes involved in lipid absorption and protein ingestion by pinocytosis and hydrolysis.…”

Percid occupation of submersed riverine macrophytes: food resource partitioning between perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus L.)

“…Perch was most active at dawn and during the day while ruffe started to eat at sunset and continued foraging during the night, exploiting its mechanoreceptors for collecting food as a specialized zoobenthos consumer (Ogle et al 1995;Hölker, Thiel 1998;Rezu, Specziár 2006;Schleuter, Eckmann 2008). Because the composition and density of macrozoobenthos indicates a decisive seasonal dynamic, ruffe compensate for a decrease in the abundance of one food type by increasing its utilization of another food type, though both types are connected with the bottom (Jamet 1994;Kangur et al 1999Kangur et al , 2003Tarvainen et al 2005). However, as our and other ecologists' results showed, the accessory food may either be zooplankton or coregonid eggs during the coregonid spawning season or else, sporadically, cyprinid eggs (Kangur, Kangur 1996).…”

The population biology and life history traits of Eurasian ruffe [Gymnocephalus cernuus (L.), Pisces: Percidae] introduced into eutrophic and oligotrophic lakes in Northern Italy

“…The food niche overlap between age classes was low in both lakes and benthic organisms, especially chironomids, were the main food items for ruffe, together with smaller amounts of zooplankton. The importance of chironomids in the diet is well-known for both northern (Kålås, 1995;Kangur et al, 1999) and southern European lakes (Lorenzoni et al, 2007). Zooplankton consumption, in contrast, is limited to summer periods and young individuals (Bergman, 1991;Kålås, 1995).…”