Abstract
The dactylogyrid monogenean Heteropriapulus heterotylus (Jogunoori, Kritsky and Venkatanarasaiah, 2004), most likely of neotropical origin, is reported from the gills of a new host, Pterygoplichthys disjunctivus (Weber, 1991), an armored catfish native to South America, collected in a reservoir on Okinawa Island, southern Japan. Illustrations and measurements are provided. This collection represents a new country and a new host record for the parasite.