Inter-specific and ontogenic differences in δ13C and δ15N values and Hg and Cd concentrations in cephalopods

摘要: Chemical tracers (e.g. stable isotopes or trace metals) are increasingly used to study trophic ecology and feeding habits of marine organisms various factors can affect their values. The aim the present was provide information on ontogenic effects carbon nitrogen values (δ 13 C δ 15 N) cadmium (Cd) mercury (Hg) concentrations in 5 cephalo- pod species from Bay Biscay (North-East Atlantic Ocean). To this end, individuals belonging 3 showing widest range sizes were analysed for muscle N mus- cle Hg, digestive gland Cd concentrations. Results showed that isotope ratios allowed dis- crimination specific strategies during ontogenesis. Segregation between cephalopod terms also evidenced (different isotopic niches). In contrast, Hg con- centrations varied over same order magnitude these species, despite higher levels benthic octopus Eledone cirrhosa. Consistently, followed pattern increased with increasing body size/age cephalopods. Finally, concen- trations orders among species. Despite possible physiol- ogy metal bioaccumulation, likely reflect pref- erences zones variability within a single Thus, have be taken into account when metals as ecological tracers; best recommendation being focus given class age.