Histopathological, hematological, condition-factor, and organ weight changes associated with selenium accumulation in fish from Belews Lake, North Carolina

Abstract

Green sunfish (Lepomis cyanellus) were collected from two study sites in Belews Lake, North Carolina, for assessment of correlations between several biological parameters and bioaccumulation of selenium. The fish had elevated concentrations of selenium in the hepatopancreas (liver) and exhibited histopathological and other manifestations of selenium poisoning. Condition-factors of Belews Lake fish were significantly correlated with selenium concentrations in hepatopancreas and skeletal muscle, indicative of capillary permeability changes and resultant edema, supported by the occurrence of significantly increased hepatopancreas-weight-to-body weight ratios in the fish having the higher tissue selenium levels. Gill lamellae were noticeably swollen and vacuolated. Hematocrits of the selenium-contaminated fish were significantly lower than those of the reference fish. The hepatopancreas exhibited lymphocyte infiltration, vacuolation of parenchymal hepatocytes around the central veins, and increased numbers of Kupffer cells. The mesonephros exhibited focal intra-capillary proliferative glomerulonephritis. Hearts showed swollen, inflammatory cell-filled pericardial spaces, diagnosed as possible uremia-induced pericarditis. Ovaries in fish with the higher liver selenium levels exhibited numerous necrotic and ruptured egg follicles. These conditions were observed in the Belews Lake Site 2 fish, but did not occur in reference green sunfish, nor did they occur consistently in fish from the less-contaminated Belews Lake Site 1.