Physiological responses to heavy metals and adaptation to increased oxygenpartial pressure in Antarctic fish and protozoa

In the first part of this study, metal bioaccumulation and metallothioneins were investigated in various organs of the red-blooded teleost, Trematomus bernacchii, and the haemoglobinless Chionodraco bamatus. Hepatic metalloth ionein correlated positively with Cd, Cu, and Zn concentrations in T. berna cchii, whereas in C. bamatus it showed a positive correlation only with Cd. A metal-linking protein with characteristics typical of metallothioneins w as identified in the liver of C. bamatus as well as of T. bernacchii. In th e second part, data on the amino acid sequence of the enzyme superoxide dis mutase (SOD) were analysed and compared with SOD sequences from other anima ls. In the third part, a low degree of tolerance against the toxic effects of copper was reported in two cilates, Pleuronema coronatum and Euplotes ra riseta, collected from Terra Nova Bay and cultured in the laboratory.