Fig. 6

Scanning electron micrographs of B. alexandrina snails (soft parts) showing A Control snails displaying normal ultrastructure of head-foot region with smooth tegmental surface of mantle and conspicuous microvilli and the tentacle with fine cilia B Higher magnification of the tentacles with a smooth surface and fine spines in the tegmental surface of mantle (the arrow). C, D Snails exposed to LC₁₀ (15.6 mg/l) of CuO NPs showing C Mantle became turgidity, rough, blebbing, peeling, and tortuosity. D Tentacles was rough with erosion at apex (the arrow). E, F Snails exposed to LC₂₅ (27.18 mg/l) of CuO NPs showing E Ruptured and peeling mantle with rough tegmental surface F Tentacles became more rough with erosion of its folds, tortuosity (the arrow) and presence of nipples (N)