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International audience The concentrations of sixteen trace elements were investigated and compared for the first time in the digestive and excreting tissues of two Nautilus species (Cephalopoda: Nautiloidea) from two geologically contrasted areas: 1) N. macromphalus from New Caledonia, a region characterised by its richness in nickel ores and its lack of tectonic activities and 2) N. pompilius from the Vanuatu archipelago showing high volcanic and tectonic activities. In both Nautilus species, results clearly highlighted that the digestive gland played a key role in the bioaccumulation and storage of Ag, Cd, Ce, Co, Cu, Fe, La, Nd, V and Zn whereas As, Cr, Mn, Ni, Pb and Se were accumulated in a greater extent in the excreting tissues (i.e. pericardial and renal appendages). Despite contrasting environments, no significant difference (P<0.05) was found between the two Nautilus species in the concentrations of most of the essential and non essential elements, including Ni and associated metals in Ni ores (i.e. Co and Mn). As nautilus lives on the outer shelf of barrier reefs, these results strongly support the hypothesis that the New Caledonian lagoon traps the major amount of the trace elements derived from natural erosion and the intense mining activities conducted on land. In contrast, the concentrations of the rare earth elements (Ce, La, and Nd) were significantly higher in N. pompilius than in N. macromphalus, probably as a result of the local enrichment of Vanuatu waters by specific environmental processes, such as volcanism or upwelling.