Ecotoxicological effects of trace element contamination in talitrid amphipod Orchestia montagui Audouin, 1826.

This study deals with the evaluation of trace element bioaccumulation and histological alterations in the hepatopancreas of the supralittoral amphipod Orchestia montagui Audouin, 1826 due to the exposure to cadmium, copper, and zinc. Orchestia montagui individuals were maintained during 14 days in soils contaminated with different trace elements namely cadmium, copper, and zinc; a control was also prepared. Our results show that the mortality and the body mass vary according to the metal and the nominal concentration used. In general, the mortality increases from the seventh day. However, the body mass shows a decrease with cadmium exposure and an increase with copper and zinc exposures. Furthermore, the concentration factor highlights that this species is considered a macroconcentrator for copper and zinc. The hepatopancreas of unexposed and exposed animals were compared to detect histological changes. Our results show significant alterations in the hepatopancreas of the exposed animals after the experiment. The degree of these alterations was found to be dose-dependent. Among the histological changes in the hepatopancreas in O. montagui, a loss of cell structure was noted, especially cell remoteness and border lyses, the reduction of nuclear volume, an increase in the cytoplasm density with the presence of trace element deposits in both the nucleus and vacuoles, a disorganization and destruction of microvilli, and a condensation of the majority of cell organelles and mitochondria swelling. Through this study, we have confirmed that O. montagui can be a relevant model to assess trace metal element pollution in Tunisian coastal lagoons with the aim of using it in future biomonitoring programs.