Elimination kinetics of tetra-, penta- and hexachlorobiphenyls (IUPAC nos. 44, 52, 87, 95, 101, 153) were investigated by laboratory experiments in three species of different phyla: Nereis diversicolor (Polychaeta), Palaemon longirostris (Crustacea) and Platichthys flesus (Pisces). Half-lives were species-specific and structure-dependent. P. longirostris eliminated all components fastest. N. diversicolor was faster than P. flesus except for components 95 and 153. Contrary to the fish species, the two invertebrates contained significant amounts of polar transformation products of no. 52, which had been applied as 14C-labelled. Therefore, the faster elimination by P. longirostris and N. diversicolor was assumed to be generally due to increased biotransformation. Elimination was in accordance with PCB residue patterns obtained from field samples of the species. Congeners with vicinal H atoms in m,p positions were under-represented in P. longirostris and so were congeners with * 7 Cl in N. diversicolor, while the PCB residue pattern in P. flesus was similar to that of Clophen A60. By comparing percentages of the experimental congeners in sigma PCB and their elimination half-lives in the three species, it was revealed that residue patterns were also influenced by species-dependent uptake, e.g. feeding habits. EOM based sigma PCB levels increased with trophic levels of the three species.