See text Pseudorhabdosynochus is a genus of monopisthocotylean monogeneans, included in the family Diplectanidae.

The digestive system includes an anterior muscular pharynx, and two lateral intestinal branches (or caeca); as in all Platyhelminthes, there is no anus.

The squamodiscs (one ventral and one dorsal) of species of Pseudorhabdosynochus are made up of numerous rodlets aligned as concentric rows.

All species of the genus have two squamodiscs except Pseudorhabdosynochus sinediscus Neifar & Euzet, 2007 in which these organs are completely lacking.

The vagina includes a sclerotized part, which is a complex structure with several chambers and canals, generally used for the diagnosis and differentiation of species.

The famous Japanese parasitologist Satyu Yamaguti described a ‘membranous plaque’ on the posterior region of Pseudorhabdosynochus epinepheli and created[1] the generic name Pseudorhabdosynochus in reference to the diplectanid genus Rhabdosynochus which, in his interpretation, also had lateral plaques.

Kritsky & Beverley-Burton (1986) [2] solved this case with reference to the International Code of Zoological Nomenclature.

The life-cycle includes a parasitic phase, the adult worm, and two stages which are free in the environment, the egg and the larva.

The adult hermaphroditic worm, which lives on the gills of fish, lays eggs in the water.

During transformation from larva to adult, the monogenean loses its cilia and produces a new tegument, a phenomenon which is considered a general characteristic of the parasitic Platyhelminthes or Neodermata.

[14] Information is available for the life-cycle of Pseudorhabdosynochus lantauensis, a parasite of the orange-spotted grouper Epinephelus coioides, at a temperature of 30 °C.

Since the life-cycle is monoxenous and thus can be completed with a high rate of success in mariculture condition, species of Pseudorhabdosynochus can proliferate on gills of cultured groupers and become dangerous for the fish, inducing mortality.

[23] Eradication of gill parasitic monogeneans is a problem because various chemical treatments can be harmful for the fish.

[citation needed] Lists of species have been provided by Kritsky & Beverley-Burton (1986)[2] and Justine (2007).