Pseudorhabdosynochus is a genus of monopisthocotylean Monogenean, included in the family Diplectanidae.The type-species of the genus is Pseudorhabdosynochus epinepheli (Yamaguti, 1938).The genus includes more than 80 species, which are all parasitic on the gills of marine fish, especially groupers. Since groupers are mostly abundant in warm waters, species of Pseudorhabdosynochus are found in warm parts of the oceans, especially in coral reefs, but species have also been found in deep-sea groupers. Several species of Pseudorhabdosynochus are pathogens of maricultured groupers.