fa Parasitic Diseases Parasitic Diseases پژوهشي Original research papers <p>Development of shrimp farming has been associated with the incidence of fatal diseases including viral, bacterial and protozoan parasites of shrimp. Our study was aimed to present an status of several important protozoan parasites of <em>F. indicus</em> in cultured earthen ponds in Iran during the period of 2011 to 2012. One hundred live shrimp&nbsp;&nbsp;were randomly prepared from the Shrimp Helleh Station in south of Iran. Prevalence and intensity were two important indices that calculated in our research. They were scraping, putting on clean slides and examined under microscope to observe the protozoan parasites. <em>Zoothamnium</em> sp. is more prevalent pathogen among peritrichous ciliates (88.66% to 79%) in pleopods. <em>Acineta</em> sp. was less prevalent in our isolations neither in pleopods nor in gills. It is concluded that, peritrichous ciliates are more frequent ciliates causing mortality in cultured shrimps at high density in higher temperature and ammonia.&nbsp;</p> F. indicus, Protozoan, Epibiont ciliates, Epicommensal 17 23 http://ijaah.ir/browse.php?a_code=A-10-35-32&slc_lang=fa&sid=1 S kakoolaki 10031947532846001170 10031947532846001170 Yes Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extention Org., Tehran,Iran M Afsharnasab 10031947532846001171 10031947532846001171 No Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extention Org., Tehran,Iran