Assessing the energetic cost of exposure to copper in a freshwater gastropod

Exposure to a toxicant has an energetic cost to an organism due to the need for metabolism and excretion of the contaminant, along with repair of any damage at the cellular or tissue level due to the toxicant. The energetic cost of survival upon exposure to a toxicant may result in complete inhibition of reproduction or a reduction in energetic resources available for developing embryos. This study investigated whether exposure of mature adult freshwater snails to copper resulted in a measurable energetic cost to the individuals. Survival, egg mass production, total antioxidant capacity, metallothionein, glycogen, protein, lipid, total energy available, electron transport system, and cellular energy allocation were measured to evaluate the energetic cost of exposure to copper. Survival was not affected by exposure to 28.8 µg/L of copper but egg mass production, glycogen, protein, lipid, total energy available, and electron transport system were reduced. A negative relationship between cellular energy allocation and concentration of exposure to copper was observed for the snails, but the relationship was not significant.