The spatial distribution of monogenean species was assessed on the gills of 102 specimens of Mormyrus rume from man-made Lake Ayame I between july 2015 and june 2016. Each gill arch was removed and examined to both quantify the number of parasites and their distribution on the gills. Monogenean species of this fish consisted of Bouixella yaoi, B. gorei and B. koutouani. All species were aggregated within the host population. The distribution of these parasites on the gills did not reveal host side preference. However, there were preferences for the specific gill arches. B. yaoi had a preference for attachment to second and third gill arches, whereas B. gorei tended to settle on the second gill arch. Both parasites, which are their robust sclerified haptorial pieces, accumulate mostly in distal part whereas B. koutouani which is weaker, prefer the proximal part of the gill. The low abundance of species recorded had indicated the absence of the intra specific or inter specific competition on the distribution of monogeneans. The volume of the parasite, the phenotype of the haptor, the respiratory water current and probably the reproduction of the parasites are the principal determinants.