Effect of season, sex and reproduction on zinc concentration in the soft tissues of Meretrix casta (Chemnitz) (Mollusca: Bivalvia) collected from Vellar Estuary, Porto Novo, India

Abstract

The investigation was undertaken to determine the impact of ecological and biological factors on the bio-accumulation of zinc in Meretrix casta collected from Vellar Estuary. The concentration of zinc in water, sediment, whole animal tissues and different soft body parts, such as adductor muscle, foot, mantle, gill, gonad and digestive diverticula of both male and female, were analysed separately. A high concentration of zinc was discernible during the monsoon, whereas it was low during summer. The metal concentration in the sediment was higher than in the water and body tissues. Among the body tissues, gill tissues showed high values followed by the mantle, digestive diverticula, gonad, foot and adductor muscle. A statistical analysis revealed a significant positive correlation between zinc concentration in body tissues and ambient medium. A significant negative relationship was encountered between salinity and zinc concentration in animal body tissues.