Histomorphological alterations induced by heavy metal, chromium in the digestive gland of an estuarine clam, mactra violacea (bivalvia: mollusca)

The median lethal concentration (LC50/96h) of Chromium Chloride for the estuarine clam, Mactra violacea was recorded to be 2.4 mg/l.  Acute chromium exposure (0.24 mg/l = 1/10th of LC50/96h) to M. violacea caused histological alterations in the chief metabolic organ namely digestive gland.  Histological studies showed that the digestive gland tissues suffered more on 72h and 96h exposures than 24h and 48h exposures.  Distinct histomorphological alterations namely epithelial degeneration, necrosis, vacuolation and granular cytoplasm were noticed in acute treated digestive diverticula of M. violacea.  Results of histopathology in the present study were dependent on the period of exposure.