Squid beaks as a proxy for mercury concentrations in muscle of the giant warty squid Moroteuthopsis longimana

Cephalopods play a major role in marine food webs as both predators and prey. Although most of the Hg in cephalopods is present in the muscle, most studies on its accumulation by predators are based on concentrations in beaks. Here, using upper and lower beaks and buccal masses of Moroteuthopsis longimana, we evaluated the relationship between Hg concentrations in different cephalopod tissues. Hg concentrations in muscle tissue (329.9 ± 166.4 ng.g−1 dw) were ≈100-fold higher than in different sections of the upper (3.5 ± 1.4 ng.g−1 dw) and lower (3.5 ± 1.0 ng.g−1 dw) beaks. A positive linear relationship was found between the Hg in the beak wing and in the muscle. Hg concentrations in the wing are therefore a useful proxy for the total Hg body burden, and their analysis provides a means of assessing the levels, transport and fate of Hg in marine ecosystems.