Pseudorhabdosynochus kritskyi
Pseudorhabdosynochus kritskyi is a diplectanid monogenean parasitic on the gills of the gag, "Mycteroperca microlepis". The species has been described by Dyer, Williams and Bunkley-Williams in 1995 and redescribed successively by Yang, Gibson and Zeng in 2005 and by Kritsky, Bakenhaster and Adams in 2015. Description. "Pseudorhabdosynochus kritskyi" is a small monogenean, less than 1 mm (700 μm) long. The species has the general characteristics of other species of "Pseudorhabdosynochus", with a flat body and a posterior haptor, which is the organ by which the monogenean attaches itself to the gill of is host. The haptor bears  two squamodiscs, one ventral and one dorsal. The sclerotized male copulatory organ, or "quadriloculate organ", has the shape of a bean with four internal chambers, as in other species of "Pseudorhabdosynochus". The vagina includes a sclerotized part, which is a complex structure. The redescription by Kritsky, Bakenhaster & Adams in 2015 includes the following: Diagnosis. According to Kritsky, Bakenhaster & Adams (2015), "Pseudorhabdosynochus kritskyi" differs from "P. vascellum" and "P. hyphessometochus" by having a large cavity within the chamber of the vaginal sclerite and from "P. vascellum" and "P. contubernalis" by having a short heavy cone of the male copulatory organ. It  is distinguished from "P. mycteropercae" by having comparatively short dorsal and ventral anchor shafts and a dorsal bar with an enlarged medial end . It differs further from these species by having more rows of rodlets in the haptoral squamodiscs. Hosts and localities. The type-host and only host of "Pseudorhabdosynochus kritskyi" is the gag, "Mycteroperca microlepis" and the type-locality is the Gulf of Mexico. Other records include Florida Middle Grounds in the Gulf of Mexico, near Mobile Bay, Alabama, and Tampa Bay, Florida.