Acute responses of brown mussel (Perna perna) exposed to sub-lethal copper levels: Integration of physiological and cellular responses

This study examined the effect of sub-lethal copper levels on selected physiological and cellular responses of the marine bivalve Perna perna. Animals were exposed to five environmentally relevant concentrations of 12.5, 25.0, 37.5 and 50.0 μg L−1 copper and metal accumulation was found to be significantly increased at the two higher copper concentrations after 24 h of exposure. Physiological responses found to increase during acute copper exposure included mucus secretion rate (at 25 and 50 μg L−1 copper), nitrogen excretion rates and oxygen consumption rates (both at 25 and 50 μg L−1 copper). Perna perna changed its substrate utilisation at 25, 37.5 and 50 μg L−1 copper in favour of protein-based metabolism. A higher degree of ROS induced DNA damage was observed at acute exposure to 37.5 and 50 μg L−1 copper. Filtration rate was unchanged during acute copper exposure.A model is proposed that integrates cellular and physiological responses to copper during short-term acute and long-term chronic exposures.