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Abstract

Understanding how seafood will be influenced by coming environmental changes is very important in research. The aim of this experiment was to compare the heavy metal and parasitic contamination from different coastal areas in Egypt (El Asafra, Eastern harbor, and El Mex). Results show that, the gonads of clam may be parasitized by parasitic castration. A quantitative histological analysis of the parasitized gonads in the present study demonstrated a significant decrease in gonadal area, in the size of individual acini, compared to un-parasitized clams. Castration may be caused by mechanical compression sporocyst growth. It is suggested that parasitic castration has a primary effect on the host?s gametogenic systems that regulate gamete production. Diseases of bivalve molluscs are noteworthy not only for their impact on population dynamics, especially of key commercial species, but also for characteristics that separate them from typical diseases affecting mammals and fish. Most described bivalve diseases are of protozoan and transmission is via the water column, as adult hosts are immobile. Transmission can occur over large distances and can be swift under favorable climatic conditions, resulting in rapid parasite proliferation and mass adult mortalities. In the present study, contamination of bivalve; Ruditapes decussatus in costal seawater of Alexandria; in three localities El Asafra, Eastern harbor, and El Mex in Alexandria were surveyed for waterborne protozoa. The results revealed the presence of Cryptosporidia, Cyclospora and Microsporidia species in the samples collected from El Max. Cryptosporidia only were collected from Eastern Harbor. Cryptosporidia and Microsporidia but not Cyclospora were infective to the gut mucosa of the Ruditapes decussatus. As eating raw or inadequately cooked Ruditapes decussatus is a common habit in Egypt, contamination of the Ruditapes decussatus by Cryptosporidia and Microsporidia may pose a threat to human health if they were among the species infecting man.

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