A laboratory study of the copper and nickel uptake and regulation in a copper - tolerant decapod, Cambarus bartoni (Fabricius) (Decapoda, Crustacea)

Abstract

Tissue copper concentration in whole Cambarus bartoni, exposed for four weeks to 0.125,0.25 and 0.5 mg Cu/litre and 0.2, 0.4 and 0.8 mg Ni/litre in the laboratory at 18°C, showed a linear relationship with exposure time at 0.25 and 0.5 mg Cu/litre; the regression slope at 0.5 mg Cu/litre (r² = 0.218; 0.001 <P≤0.05) was approximately two times higher than that at 0.25 mg Cu/litre (r² = 0.148; 0.025 < P≤0.05). Regression analysis of nickel concentrations in whole crayfish as a function of exposure time showed a third degree polynomial relationship at 0.4 (y = 49.989 + 14.77x-15.395x² + 3.194x³) and 0.8 (y = 52.053 + 37.05x - 28.933x² + 5.133x³) mg Ni/litre, as well as in the control (y = 49.126 + 27.253x - 23.468x² + 4.168x³) (y = Ni concentration; x = exposure time in weeks), suggesting the occurrence of a Ni flux every 4 weeks.