DAO 22:51-57 (1995) - doi:10.3354/dao022051
Copper-induced damage to the hepatopancreas of the penaeid shrimp Metapenaeus dobsoni - an ultrastructural study
Manisseri MK, Menon NR
The hepatopancreas of decapod crustaceans has been recognised as an important target organ for studying the effects of heavy metal pollution. This dynamic organ, with its capability of detoxifying heavy metals through lysosomal activities, often indicates distinct pathological disturbances. This led to the present investigation in which we examined the ultrastructure of hepatopancreas of the penaeid shrimp Metapenaeus dobsoni (Miers) exposed to culture medium containing 50 and 150 ppb of copper. After an exposure period of 15 d, the hepatopancreas was dissected from individuals belonging to the intermoult stage and the structure studied employing transmission electron microscopy. Structural deformities of the cells were not confined to a specific inclusion. Instead, subcellular organelles including the endoplasmic reticulum, mitochondria, basal lamina, and nucleus showed damage of varying degrees. Damage to the nucleus and its inclusions would have a profound effect on its functioning. Endoplasmic reticulum and mitochondria showed partial to total disintegration which probably would have made them non-functional. Smooth endoplasmic reticulum, the prime organelle for detoxification and lipid synthesis, also showed damage, indicating the possibility of a disruption of the cellular detoxification mechanism. Although at lower levels (50 ppb) copper was found to induce a biphasic effect on the histology and histochemistry of the hepatopancreas, this was not reflected in the nature of structural damage of the subcellular organelles performing vital functions. Presence of electron-dense granules in the haemolymph and epithelial cells is indicative of the role played by these granules in detoxification or demobilisation of copper.
Copper-induced damage . Hepatopancreas . Metapenaeus dobsoni
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