Résumé
A study of Oreochromis niloticus (Linnaeus), O. aureus (Steindachner), Sarotherodon caudomarginatus (Boulenger), S. galilaeus (Linnaeus) and S. galilaeus sanagaensis (Thys van den Audenaerde) (Teleostei, Cichlidae) from different locations in Africa (Burkina Faso, Cameroon, Guinea, Niger and Senegal) revealed the presence of 11 species of monogenean gill parasites. Four, belonging to Cichlidogyrus Paperna, 1960 and considered as new species, are described: C. rognoni n. sp., C. douellouae n. sp., C. giostrai n. sp. and C. njinei n. sp. They are distinguished by the shape and/or size of the sclerotised parts of the haptoral and copulatory complexes. C. thurstonae Ergens, 1981 from O. niloticus is redescribed.