Monogenean parasites from Clariidae (Teleostei, siluriformes) in Cameroon:: I.: Description of two new species of Gryodactylus from the Nyong Bassin

The study of gill and skin parasites of three fishes species belonging to the genus Clarias: C. camerunensis, C. jaensis and C. pachynema, from the Nyong basin (Cameroon), revealed the presence of two new Monogenean species of the genus Gyrodactylus Nordmann: G. camerunensis n. sp. and G. nyongensis n. sp. parasite of Clarias camerunensis, C. jaensis and C. pachynema. Gyrodactylus camerunensis n. sp. is clearly distinguished from G. nyongensis n. sp. by the smaller size of the haptor sclerites. These two new species differ also from their closest african relatives of the genus Gyrodactylus, G. rysavyi, G. clarii and G. alberti, by the morpholohy and size of the haptorail sclerites. Their host specificity was discussed and appeared stenoxenous (mesostenoxenous).