TRACE-ELEMENTS IN CRAYFISH - REGIONAL DIFFERENCES AND CHANGES INDUCEDBY COOKING

The concentrations of Pb, Cd, Zn, Cu, Ni, Cr, Mn, Co, As, and Se were determined in the abdominal muscle and hepatopancreas from raw and coo ked crayfish of Astacus astacus (L.) and Pacifastacus leniusculus (Dan a), both of Swedish origin. After cooking, the concentrations of Cd, N i, and Co in the hepatopancreas showed a decrease and the concentratio ns of Pb, Cu, and Mn in the abdominal muscle showed an increase. Metal and metalloid concentrations were also determined in the abdominal mu scle and hepatopancreas of commercially caught and cooked crayfish, in cluding Astacus leptodactylus (Esch.) and Procambarus clarkii (Girard) , from China, Spain, Sweden, Turkey, and USA. Most of the elements sho wed little variation except for cadmium in the abdominal muscle of P. leniusculus from California, which was markedly higher (mean = 0.082 m g/kg) than the others (mean = 0.004 mg/kg). Metal and metalloid concen trations in hepatopancreas varied greatly within as well as between co untries. In the hepatopancreas from P. leniusculus from a Swedish lake the manganese concentrations were markedly higher than in any other c rayfish. The intake of cadmium from crayfish inhabiting uncontaminated waters will be low if the hepatopancreas is not consumed.