Histopathological alternations of blood clam Tegillarca granosa in acute copper, zinc, lead and cadmium exposures

摘要

Blood clam, Tegillarca granosa, facing increasing danger of heavy metal contamination. In order to investigate the toxicological effect of copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) on T. granosa, histopathological alternations were investigated in present study. Based on histopathological observation, Cu, Pb and Cd showed different degrees of damages to gills range from gill degeneration, gill fusion to interlamellar space and cilia reduction. In general, the more toxic the more severe damages to gills were observed. Massive oocytes degeneration in female gonad, muscle fiber degeneration and increased gap between muscle fibers in foot were found in Cd-exposure-treated T. granosa. Zn exposure induced an increase of epidermis wrinkles and a reduction of inner gaps. The results reveal different toxic mechanisms of tested heavy metals on T. granosa.