Fig. 6 After 7 days of exposure to different concentrations of copper
(Cu), lead (Pb), or Cu+Pb, light microscopy was performed on
S. cymosum samples stained with TB-O. a Control treatment. Observe
cortical cells (CC) showing metachromatic reaction in the cell walls
(CW), indicating the presence of acidic polysaccharides and some
physodes in blue and yellow (arrows). b–d Cu treatments. Observe the
increasing quantity of physodes in metal-treated samples and their migration
toward cortical cells (arrows). e–g Pb treatments. h–j Cu+Pb treatments.
Note the presence of physodes (arrows)