Pseudorhabdosynochus kasetsartensis n. sp. (Monogenea: Diplectanidae) from the cloudy grouper Epinephelus erythrurus (Valenciennes) (Perciformes: Serranidae) in the lower Gulf of Thailand.

Pseudorhabdosynochus kasetsartensis n. sp. is described from the gills of the cloudy grouper Epinephelus erythrurus (Valenciennes) caught in the lower Gulf of Thailand. The new species is distinguished from other species assigned to the genus by the structure of its sclerotised vagina which has a wide and prominent sclerotised trumpet, long, thin, coiled or curved primary canal, short secondary canal, and primary and secondary chambers that are blind extremities of the primary and secondary canals, respectively. This is the first species of Pseudorhabdosynochus Yamaguti, 1958 described from E. erythrurus and the first record of a species of Pseudorhabdosynochus in Thailand.