Abstract-Temperature is an important controlling factor in the metabolism of ectotherms, and it may interact with the toxicity of heavy metals in a variety of ways. In this work, a study on the effect of different zinc concentrations (0.3, 13, 26, and 40 mol/ g dry litter) on growth (body weight) of the isopod Porcellio scaber was conducted using four temperature levels (12, 16, 20, and 24ЊC). The results demonstrated a significant effect for both zinc and temperature on the growth rate; the interaction between zinc and temperature was also significant. The Arrhenius function was used to describe the temperature-growth rate relationship, from which estimates for the activation energy were derived. A tendency for activation energy to decrease with increasing zinc concentration was observed. Isopods exposed to 13 mol Zn/g had the highest activation energy and the highest growth rate. To analyze the effect of temperature on the internal body concentration of zinc, the exposure time was transformed into physiological time, calibrated at 15ЊC, for all experimental groups using the activation energies estimated earlier. The rate of zinc accumulation was derived from the relationship between internal body concentration and physiological exposure time. Differences between isopods cultured at different temperatures could be explained well by the effect of physiological exposure time. The interaction between temperature and zinc toxicity seems to be due not to increased accumulation of zinc at higher temperatures as such but to a physiological interaction with the energy metabolism.

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