Parasites of cultured oyster (Crassostrea iredalei)

Abstract

This study was carried out to identify the parasites found in oyster ( Crassostrea iredalei), the prevalence and the mean intensity of parasites found and the relationship between the prevalence of parasites found with the water parameters (DO, pH, salinity, and temperature). A total of 40 oysters were obtained from the raft culture in Setiu and Merchang, then placed in aquarium and brought to the laboratory for examination. The water parameters at sampling site were tested and recorded by pH meter, DO meter and salinity meter. The shell's oyster was opened and the various part of the oyster was examined. Smear was made by scraping mucous from the various parts of the oyster, put on the glass slide and then examined under microscope for parasites observation. Giemsa's stain was used to stain for identification. One species of dinoflagellate and one species of ciliate have been found. The dinoflagellate closely resembled Amylodinium ocellatum and the ciliate closely resembled Trachelius sp. The prevalence and the mean intensity of dinoflagellate were 80% and 33.09 while the ciliate were 97.5% and 92.9 respectively. The prevalence of both ciliate and dinoflagellate were not correlated with all the water parameters (DO, pH, salinity, and temperature) where the Spearsman' s rho Correlation test showed that the relationship were not significantly different (P>0.05).