SEX- AND MATURITY-RELATED HEAVY METAL ACCUMULATIONS IN THE ANTARCTIC KRILL EUPHAUSIA SUPERBA (Eleventh Symposium on Polar Biology)

Concentrations of heavy metals and their chemical forms were analyzed in the Antarctic krill (Euphausia superba) collected from the Scotia Sea in December, 1987, and the results were discussed in relation to sex and maturity stages. The whole body metal concentrations were in the order of Zn〓Cu>Fe>Mn>Ni>Cd. The values of Fe, Mn and Zn were higher in females than in males. The values of Cu, Fe, Ni and Cd in adult females were highest in stage IIIA. Also, the values for Cu was higher in juveniles than in adults. Concentrations of the metals were generally higher in cephalothorax than in abdomen. In particular, a majority of Cu burden in the cephalothorax existed as Cu-binding proteins, which were likely to be mainly hemocyanin and metallothionein. We speculate that changes in amounts of Cu-binding proteins by physiological conditions might be important causes for the variations of Cu concentration between sexes and between maturity stages of the Antarctic krill