Age-related differences in element concentration in tissues of ruffe (Gymnocephalus cernua) and European perch (Perca fluviatilis), caught in the Danube River near Belgrade

Abstract

Concentrations of As, Cr, Fe, Hg, Mn, Se and Zn were assessed by ICP-OES in muscle, gills, liver and gonads of ruffe and European perch of different age classes. Fish were caughtwith portablefish nets at the confluence of the Danube river and the Sava River, in Belgrade. Age-related differences in element concentration were assessed by ANOVA and Tukeys (HSD) tests. In ruffe, liver is the main tissue for accumulation of Cu, Fe and Se in all age classes. Gills are the main tissue for accumalation of Mn, while gonads had a higher concentrations of all elements in liver (exept for Cr), while individuals aged 4+ had the highest element concentration in gonads (again, with the exception of Cr). However, these age-related differences in ruffe were not statistically significant. In European perch, the highest concentrations of As, Cu, Fe, Se and Zn in majority of age classes were found in the liver. Individuals aged 1+ and 2+ had the highest concentration of Hg in gills. In subsequent age classes, muscle was the main tissue for accumulation of this element. Contrary to ruffe, age-related differences were observed for Se in liver, where age classes 4+ and 5+ had higher concentrations than age-class 1+, as well as for Zn in gonads, where age classes 4+ and 5+ had higher concentrations than age-class 1+, as well as for zn in gonads, where age class 1+ had higher concentration than age class 3+.