ABSTRACT

The kuruma prawn Marsupenaeus japonicus is considered as one of the luxury seafood in Alexandria, Mediterranean Sea, Egypt. The present study is designed to determine the seasonal bioaccumulation of Zn, Cu, Fe, Pd, Cd and Co in the whole soft tissues as well as in the ovary of M. japonicus collected from Abu-Qir bay. The kuruma prawn accumulates metals in soft tissues and gonads at concentrations exceeding that of seawater. The order of metals bioaccumulation levels was Zn >Fe >Cu >Pb> Cd>Co. Metals in the whole soft tissues as well as the ovary showed seasonal variations. For all metals, the highest concentrations were detected in summer, while the lowest were in winter. Results revealed that only the bioaccumulation levels of Zn and Fe in kuruma prawn were found to be higher than the permissible limits for human consumption. Moreover, the level of the caloric contents of the soft tissues of M. japonicus was evaluated and seasonal variations were recorded. The seasonal total protein contents in the soft tissues of M. japonicus were arranged as followed: summer > spring > autumn > winter. In contrast, the highest content of total carbohydrates and total lipids was in winter, while their lowest content was in summer. The present study extended also to histological studies of the ovary of M. japonicus at different stages of maturation. Several stages of ovarian cycle of maturation recorded marked histopathological alterations.