Distribution of macrophage centres in bream (Abramis brama L.) liver from the oder river (Germany/Poland) within the nature reserve "unteres odertal" near the town of schwedt

Abstract

The livers of bream (Abramis brama) from the Oder River near the town of Schwedt (Germany), were investigated for their content of macrophage centres (MCs). The investigations were carried out for a period of 18 months. The mean MC-number was 20 ± 14 MCs per mm2 in females and 13 ± 11 MCs per mm2 in males. These values are regarded as normal for adult bream of the Oder River. The diameter of the MCs ranged between 8 and 160 μm for both sexes. The study showed positive correlations between the MC-response and water pH as well as water temperature. Different correlations existed between males and females and the water temperature. The use of histological analyses of liver MC-size and -number as a biomarker is discussed. Currently the MC-response is only regarded as an unspecific biomarker on environmental stress.