Accumulation of mercury and its impact on the chloride cell of gills of tilapia (Oreochromis niloticus linnaeus, 1758)

The objectives of this study were to analyze and to compare the exposure effects of mercury (Hg) acculmulation and its impact to the chloride cell of the gills of East Java strain tilapia (Oreochromis niloticus). The fish specimens were exposed to 0 mg/L, 0.1 mg/L, and 1 mg/L concentrations of Hg. After 96 hours (96h) exposure, Hg accumulation in fish gills were assessed, gills structure, and Na⁺/K⁺-ATPase (NKA) immunohistochemistry (IHC) were observed under the light microscope. The mercury concentrations in gills of mercury-exposed fish were signicantly higher at 1 mg/L than 0.1 mg/L and control groups. Positive NKA expression in chloride cell (CC) was observed along the primary and secondary lamellae of gills of tilapia. The waterborne exposure route demonstrated the most significant microscopic damage in higher concentration of Hg.