Vampyrophrya pelagica (Chatton and Lwoff 1930), an apostome ciliate infectious on calanoid copepod from the Northeastern Arabian Sea

Abstract Background Zooplankton provides a dynamic habitat to various kinds of epibionts in the marine ecosystem and also forms source food nutrients parasites parasitoids. The study was conducted identify association ciliates with calanoid copepod Northeastern Arabian Sea. samples collected were analysed under stereomicroscope for any kind ciliate attachments. infective stage major characteristics discussed. present observation is first report apostome Vampyrophrya pelagica on Bestiolina similis from open ocean waters off Tarapur, Sea, during early spring intermonsoon season new host record ciliate. Results Analysis ~ 2530 revealed presence 12 specimens infested pelagica. All copepod, identified as similis, females. Approximately 50–60 occupied endocuticular region. V. represented by fully grown trophont characterized large vacuole surrounded thin layer cytoplasm numerous lipid bodies. Conclusion establishes record, B. its Indian extends biogeographic boundary