Updated project metadata. Ectoparasitic flatworms from the family Diplozoidae (Platyhelminthes: Monogenea) represent serious hematophagous fish pathogens. Information related to the biochemical and molecular nature of the physiological processes is rather sporadic, as well as the knowledge of the molecules produced by monogeneans and their role in host-parasite interaction. Therefore, we performed a complex secretomic analysis of monogenean representative Eudiplozoon nipponicum for the purpose to identify functionally important protein molecules involved in these host-parasite interactions.