No abstract

The present paper aims to study the occurrence of monogenean species infecting the gills of wild Hemichromis elongatus (Pisces). Fish specimens were caught with nets, fixed in 10% formalin and then dissected. Monogenean specimens found were removed under a stereomicroscope with a needle, and then mounted between slide and cover slip in a drop of hematoxylin eosin. Among the five parasite species found, only O. voltaensis and C. euzeti were found infesting their host alone. There were significant differences between mono-parasitism and polyparasitism both in parasite load and infection rate, which were higher in simultaneous infestations. These monogenean ectoparasites best exploit their common host when they co-occur. This phenomenon observed in natural conditions is a threat in fish farming where high host densities favor parasite transmission. We therefore recommend quarantining native fish specimens captured in the wild, periodic pond sanitization and deworming.