Pseudorhabdosynochus regius is a diplectanid monogenean parasitic on the gills of the mottled grouper (Mycteroperca rubra).

The haptor bears two squamodiscs, one ventral and one dorsal, which are small, with a length of 20-40 μm, and made up of only 10-11 rows of rodlets.

[2] The vagina includes a sclerotized part, which is a complex structure, 26-35 μm in length.

The monogenean has also been found on fish of the same species caught off Sfax, Tunisia and off Tripoli, Libya.

Only 14 species of diplectanids parasitic on groupers are known in the Mediterranean Sea and P. regius is one of them.