Histological Changes of Electric Yellow Cichlid (Labidochromis caeruleus) Exposed to Acute and Chronic Cadmium Concentrations

Abstract

In this study, electric yellow cichlid were (Labidochromis caeruleus) exposed to acute cadmium (Cd) concentrations (0, 50, 60, 70, 80 mg l-1) for 72 h, and chronic Cd concentrations (0.00, 0.25, 0.50, 1.00, 2.00 mg l-1) for 20 d to examine histological alternation. In addition to the recovery was detected after 10 d. After chronic trial, rest of the fish were exposed to just water not containing cadmium for 10 day for recovery. Gills, liver, muscle, and spleen samples were collected from randomly selected fish. The tissue samples prepared with standard techniques for haematoxylin and eosin (H&E). Cadmium depending on concentrations increase caused severe disorders on fish. After acute exposure, several changes were detected such as edema, hyperplasia, breakdown in epithelial tissues of gills; vacuolation and necrosis in liver; increase of hemosterin clustering and necrosis in spleen. After chronic exposure, some symptoms were also found such as edema, aneurysm, degermation of secondary lamellae in gills; degeneration and necrosis in liver; degeneration and granulomas in spleen. Additionally, after recovery of chronic Cd exposure some of the same symptoms were observed such as edema, hyperplasia and aneurysm in gills; vacuolar degeneration and necrosis in liver; granulomas and degeneration in spleen.