Effects of copper sulphate on Tisbe holothuriae Humes (Copepoda) and development of tolerance to copper

A study was made of the toxicity of copper to the marine copepod Tisbe holothuriae Humes and the development of increased tolerance due to acclimation. In sublethal concentrations, copper causes a prolongation of maturation time and a reduction in offspring production. These effects increased proportionally to the copper concentration used, while the respiratory rate (measured at the highest concentration used: 0.008 mg l^–1 Cu) increased. A tendency for higher tolerance due to acclimation was also observed. The copper induced delay in maturation time observed in the F₂ generation, became less pronounced from F₃ onwards. In animals exposed at 0.008 mg l^–1 Cu the maturation time of F₃ was not statistically different from that of untreated animals. The LC50 48 h also presented an increase due to acclimation in animals exposed at 0.004 (F₅) and 0.008 mg l^–1 Cu (F₃ and F₅ generations), but this increase was not statistically significant.