The food of common bream (Abramis brama L.) in a biomanipulated water supply reservoir

Abstract

Food composition of common bream (Abramis brama, L.) 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.

Keywords

• diet
• <i>Abramis brama</i>
• impoundment
• biomanipulation