Heavy metal concentrations in tapeworms Diploposthe laevis and Microsomacanthus compressa parasitizing aquatic birds

Two parasite-host systems tapeworms Diploposthe laevis and h Microsomacanth us compressa vs, final hosts aquatic birds Aythya lerina and A. nyroca were analysed by atomic absorption spectrometry for heavy metal (Pb, Cd, Cr, Nj ) concentrations and compared with those found in muscles and liver of the final hosts. The ability of adult tapeworms to accumulate different concentrations was g reater than that of their hosts' tissues. The value ratios of the heavy met al concentration in D. laevis, (2.0-3.6) and M. compressa (2.3-22.3), respe ctively were higher than those in their final hosts' tissues. The percentag e proportion rank of individual heavy metals in the combined sample of stro bilae of the above tapeworm species and in the sample of their hosts tissue s indicates the highest proportion in Pb (40.6-57.9 %) followed by that in Ni, Cr and Cd, except for the highest proportion of Cr in the liver of A. n yroca, followed by successively decreasing concentrations of Pb, Ni and Cd.