Quantification and histopathological alterations produced by sublethal concentrations of copper in Fundulus heteroclitus

Abstract

Fed and starved Fundulus heteroclitus specimens were exposed for 30 days to sublethal copper concentrations (800 µg Cu²⁺/L). The accumulation of copper and histopathological effects on the liver and gills were studied. In both fed and starved specimens, the liver showed a progressive copper accumulation during the experimental period (from 2 to 30 days), with higher levels of copper in the liver of starved fish. Copper accumulation was also detected in the gills, and the specimens exposed to copper for 15 to 30 days (both fed and starved) showed significant differences (P < 0.005) with respect to the control group and the 2-day treated fishes. The main histopathological alterations were: vacuolization of hepatic parenchyma, desquamation of gill epithelia, lamellar telangiectasia, as well as hepatic and branchial necrosis. The results of this paper provide evidence that the nutritional status of the fish has great importance in modifying its response to sublethal copper effects.