First Study on Gyrodactylus (Monogenea: Gyrodactylidae) in Morocco, with Description of a New Species from Luciobarbus pallaryi and Luciobarbus ksibi (Actinopterygii: Cyprinidae)

SIMPLE SUMMARY: Monogenean flatworms are mainly parasitic in lower aquatic vertebrates including fish, anurans and chelonians. Gyrodactylus is one of the 23 genera of Gyrodactylidae. With only 41 species described, the total number of Gyrodactylus species described from African freshwater fish still remains low. The known species represent only a fraction of the expected species richness of Gyrodactylus in Africa. In this study, we examined the gills of 738 cyprinid specimens. We isolated 26 individuals belonging to Gyrodactylus from these hosts. Twelve of these from two host species were morphologically characterized and proposed to belong to one single newly described species. In view of the importance of the cyprinid–monogenean system in studying the aquatic biodiversity and biogeography of North Africa, the present study is a substantial contribution to the parasite species inventory of these fishes. ABSTRACT: To date, 41 species of Gyrodactylus have been described from Africa. However, none of these have been reported in Morocco. After identifying and examining 738 cyprinid host specimens, 26 specimens belonging to Gyrodactylus were found to parasitize the gills of nine species of Luciobarbus, Carasobarbus, and Pterocapoeta. The current study provides new information about the presence of a new parasitic species in Morocco, the first to be characterized on a species level in the Maghreb region. It describes in detail 12 specimens of Gyrodactylus isolated from the gills of Luciobarbus pallaryi (Pellegrin, 1919) and Luciobarbus ksibi (Boulenger, 1905). Based on morphoanatomical observations, the characterization of the specimens collected indicates a species of Gyrodactylus that is new to science, described here as Gyrodactylus nyingiae n. sp. The new species is different from previously described gyrodactylids infecting African cyprinid hosts because it has a longer hamulus total length, a longer hamulus root, a downward projecting toe of the marginal hook, and a trapezium-shaped ventral bar membrane with a slightly striated median portion and small rounded anterolateral processes. This study increases the total number of Gyrodactylus spp. found in African cyprinids to four.