Improvements in metal exposure assays: artificial food to assess bioaccumulation in the blue crab Callinectes danae Smith, 1869 (Crustacea, Decapoda, Portunidae)

This technical note aims to report, in detail, the development, suitability and analytical validation of an artificial food to assess metal bioaccumulation in the blue crab Callinectes danae after metal exposure assays. For this purpose, lead (Pb) was chosen as the metal of interest. First, a non-contaminated artificial food was prepared by mixing commercial shrimps and agarose. The food was then offered on alternate days to two groups of crabs for 7 and 14 days, respectively. After confirming that this food was well-accepted by crabs, analytical procedures were performed to confirm that Pb added to the mixture would remain in the artificial food. For this purpose, two foods containing Pb at concentrations of 0.5 and 2.0 µg g−1 were prepared by adding aliquots of an ultrapure Pb standard solution to the mixture. Samples of each food were subjected to an acid extraction and Pb concentrations were determined by a GF-AAS. Pb recoveries in both contaminated foods were > 90%. Subsequently, another experiment was performed, and two groups of crabs were fed with contaminated artificial foods (0.5 and 2.0 µg g−1 of Pb) during 7 and 14 days, respectively. The observed acceptance of these foods by crabs at both Pb concentrations was of 100%.