Responses of Orchestia Montagui (Amphipoda, Talitridae) to Copper and Zinc Mixture

The hepatopancreas of crustacean species has been recognized as an important target organ for studying the toxic effects of trace metals (TM). This dynamic organ, with its capability of detoxifying trace metals, often indicates distinct pathological disturbances. This study dealt with the evaluation of the histological alterations in the hepatopancreas of the supralittoral amphipod Orchestia montagui Audouin, 1826 exposed to a mixture of copper and zinc. After exposure, the hepatopancreas was dissected and its ultrastructure was observed using transmission electron microscopy. The obtained results showed that the body mass differed from the control organisms depending on the nominal metal concentration to which they were exposed. The hepatopancreas of unexposed and exposed animals were compared for the detection of histological changes. Significant dose-dependent alterations were noted in all the treatment groups. Among these histological changes of the hepatopancreas in O. montagui, we noted the loss of cell structure, especially cell remoteness and border lyses, a reduction in the nuclear volume, an increase in cytoplasm density with trace metals in both nucleus and vacuoles, a disorganization and destruction of microvilli and a condensation of the majority of cell organelles, and mitochondria swelling. Through this study, O. montagui could be a good indicator providing measurable responses. It could be an attractive candidate for the biochemical study of TM toxicity in coastal ecosystems.