Animals were fed once a week during the bioassay with goldfish flakes (TetraFin). At 48 h and at 7,
14 and 21 days after the exposure, visual observation of the organisms
was performed according to Kristoff et al. (2006) and Bianco
et al. (2013), then, soft parts of one snail per vessel were separated
from the shell and homogenized (a total of eight control snails and
eight treated snails per day). Activity of ChEs and CEs and protein
content were also measured at 48 h and at 7, 14 and 21 days after
exposure.