Distribution and accumulation of Cd in Ligia cinerascens and its effect on ultrastructure of hepatopancreas

Marine isopod Ligia cinerascens (♂1:1♀) was collected to determine the distribution and accumulation of cadmium (Cd) in their bodies or tissues and its consequent effect on the ultrastructure of the hepatopancreas. Field investigation and Cd exposure experiments indicated that male and female animals consistently bioaccumulated Cd. The hepatopancreas possessed the highest level of Cd, followed by the exoskeleton and pereiopod. The Cd concentration of exposure group in hepatopancreas was 46-fold in male and 41-fold in female higher than the control group, indicating that the hepatopancreas is a reservoir pool of Cd. The excessive Cd resulted in the disorganization of cellular structures such as microvilli, basal labyrinth, mitochondria and rough endoplasmic reticulum, and with Cd accumulated as insoluble granules in the vesicles and/or lysosomes. Based on qualitative and quantitative analysis, the ultrastructural alteration of the hepatopancreas could be used as biomarkers when utilizing the species L. cinerascens to monitor marine metal pollution.