Prevalence of Protozoan Parasites Cryptosporidium sp. and Callimastix equi in the Edible Oyster Saccostrea cucullata and Its Relationship with Selected Water Quality Parameters in Sundarbans Region of West Bengal, India.

PURPOSE: Prevalence of protozoan parasites Cryptosporidium sp. and Callimastix equi in the edible oyster resources Saccostrea cucullata, and its relationship with selected water quality parameters such as temperature, pH and salinity in Sundarbans region of West Bengal, India, have been assessed and discussed elaborately.

METHODS: Edible oysters S. cucullata were collected randomly from the selected study site Frasergunj of Sundarbans region and protozoan parasites such as Cryptosporidium sp. and C. equi were isolated, stained and determined its prevalence. Relationship of water temperature, pH and salinity with the prevalence of protozoan parasite had been assessed and analyzed.

RESULTS: Prevalence of infection of Cryptosporidium sp. is much more than the C. equi found in S. cucullata. The infections of the parasites are higher during monsoon then pre-monsoon season. Significant negative correlation (P < 0.05) occurs between pH of water and prevalence of Cryptosporidium sp. and C. equi in the edible oyster S. cucullata collected from Frasergunj of Sundarbans region, South 24 Parganas of West Bengal. The C. equi parasite follows a seasonal pattern of infection varying significantly with salinity (P < 0.01) of the water in the edible oyster, S. cucullata collected from Frasergunj of South 24 Parganas of West Bengal.

CONCLUSION: These results indicate that the Cryptosporidium sp. and C. equi contamination is accompanying with public health risks if edible oysters are consumed uncooked of undercooked. Extremes and/or rapid fluctuations of important environmental factors such as water temperature, salinity, pH can seriously compromise oyster health and outcome of aquaculture.