Subcellular partitioning on Gammarus fossarum

Male gammarids were exposed to waterborne Cd (0.3, 1, and 3 µg/L), Pb (2, 10, and 50 µg/L), and Ni (0.2, and 1 µg/L) for three weeks. All the experiments were carried out in 12 ± 0.5 °C water baths. Male gammarids (n = 160 per condition, 8 replicates of 20 size-calibrated males) were randomly placed in 500 mL-beakers in polypropylene. During exposure, organisms were fed on alder leaves (<em>Alnus glutinosa</em>). Continuous exposure was provided (exposure medium renewed four times a day). Briefly, a stock solution was prepared daily and used to obtain all tested exposure media. Peristaltic pumps were used to dilute the stock solution and obtain the highest tested concentration, which was in turn diluted to obtain the lowest concentrations. The dilution factors were established by controlling the flow of water and stock solution or intermediate dilution. On each sampling day (days 0, 4, 8, 16 and 21), amphipods (3 replicates of 10 individuals) were randomly sampled from all the beakers. They were gently dried with a paper towel, weighed (± 0.1 mg), and stored at -80 °C until compartmentalization analyses. The procedure for determining the metal subcellular distribution and metal analyses in all subcellular fractions was described previously in Geffard et al. (2010b). Data obtained are presented in related dataset