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Water moss as a food item of the zoobenthos in the Yenisei River Texto completo
2011
Kalachova, Galina | Gladyshev, Michail | Sushchik, Nadezhda | Makhutova, Olesia
Bryophytes are abundant in streams and are a habitat for many invertebrates, but their contribution to the diet of fluvial zoobenthos is still debated. To estimate the amount of bryophyte-derived organic matter assimilated by benthic invertebrates, we used a combination of fatty acid and stable isotope analyses during a four-year monthly study of a littoral site in the Yenisei River (Siberia, Russia). Acetylenic acids, which are highly specific biomarkers of the water moss Fontinalis antipyretica, were found in lipids of all dominant benthic animals: gammarids, ephemeropterans, chironomids and trichopterans. The dominant zoobenthic species, Eulimnogammarus viridis, had maximum levels of the biomarkers in its biomass during winter, and minimum levels in summer. The zoobenthos in the studied site regularly consume and assimilate bryophyte-derived organic matter as a minor supplemental food. This consumption increases in winter, when the main food source of the zoobenthos, epilithic biofilms, are probably scarce.
Mostrar más [+] Menos [-]The food of common bream (Abramis brama L.) in a biomanipulated water supply reservoir Texto completo
2012
Zapletal, T., Mendelova Univ., Brno (Czech Republic). Ustav Zoologie, Rybarstvi, Hydrobiologie a Vcelarstvi | Mares, J., Mendelova Univ., Brno (Czech Republic). Ustav Zoologie, Rybarstvi, Hydrobiologie a Vcelarstvi | Jurajda, P., Akademie Ved, Brno (Czech Republic). Ustav Biologie Obratlovcu | Vsetickova, L., Akademie Ved, Brno (Czech Republic). Ustav Biologie Obratlovcu
Food composition of Abramis brama was studied in the shallow, meso-eutrophic Hamry reservoir (Czech Republic). Fish were sampled during the daytime in the pre-spawning period (April), the post-spawning (June), summer (July) and autumn (October) in 2011. The bream sampled comprised two main size groups: small (124-186 mm) and large (210-315 mm) standard length. Twenty specimens of each size group (except April - 40 large fish) were taken for analysis on each sampling occasion. Food composition was evaluated using gravimetric methods. Over the whole season, detritus and aquatic vegetation were the dominant dietary items taken. During summer, the diet of large bream comprised mainly aquatic vegetation. Benthic macroinvertebrates and zooplankton formed a minor part of bream diet over the whole season. Specific food habits of bream could be explained by specific conditions within the reservoir and available food resources.
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