PREVALENCE AND SEASONAL ABUNDANCE OF PROTOZOAN PARASITES IN PENAEID SHRIMP PENAEUS MONODON IN HIGH SALINE BHERIES OF WEST BENGAL

摘要

Prevalence and seasonal abundance of protozoan parasites in penaeid shrimp (Penaeus monodon) of high saline bheries of West Bengal was carried out for a period of 20 months from February 2000 to November 2001 covering two successive cropping seasons. The water quality parameters like temperature, hardness and salinity influenced the prevalence and distribution of parasites. These variables have definite impact individually or as a whole on the prevalence of parasites of shrimp.The protozoan ectoparasites identified commonly were Zoothamnium sp, Vorticella sp, Epistylis sp and Acineta sp. The only endoparasite found was microsporidians (Nosema sp) with low Parasitic Frequency Index (PFI). Monsoon was found to be the most favorable season for almost all the parasites (Zoothamnium sp, Vorticella sp, Epistylis sp, Nosema sp) except Acineta sp, which showed it's proliferation in summer season.