A laboratory Study: Effect of Cadmium Chloride on Biochemical Parameters and Histological Changes in Freshwater Mussel (Unio tigridis)

The present study investigated the toxicity of cadmium (Cd) to the freshwater mussel Unio tigridis. Mussels were treated with six doses of cadmium chloride (CdCl2) control (0), 1, 2, 3, 4, and 5 ppm for up to 96 hours. The Cd accumulation and oxidative stress markers, including Acetylcholinesterase (AChE), malondialdehyde (MDA), reduced glutathione (GSH), and catalase (CAT) rather than histological changes were evaluated. Results showed that exposure to CdCl2 induced a significant increase in MDA levels and CAT activity. Notably, a significant decrease was observed in the AChE and GSH levels in the groups exposed to CdCl₂, which was dependent on exposure time. The cadmium (Cd) concentrations in both aquarium water and the mussel’s body have fluctuated, and these changes were influenced by the concentration and duration of the exposure. Histological investigation of the mussel gills showed alternation in gill structure after being exposed to different cadmium concentrations when compared to the control group.