Prevalence and intensity of gill monogenean parasites of Tilapia guineensis (Bleeker, 1862) in man-made Lake Ayamé 2, Côte d’Ivoire according to season, host size and sex

Abstract

The study of the gills of 361 Tilapia guineensis was conducted from July 2015 to June 2016 to determine the effect of seasonal changes, host size and sex on the incidence of monogenean parasites infection. Standard methods of parasitological examination were used for identification of monogenean species. Eleven species were identified. Seasonal changes in the rates of infection for all the monogenean  species were found. The highest values of prevalence and mean intensity were  observed in the rainy seasons and the lowest values in the long dry season,  particularly. The parasite load of all monogenean except of Cichlidogyrus kouassii increased with the size of the fish. It also showed that the sex of the host influenced the parasites burden. The intensities of infection of C. vexus, C. ergensis, C. cubitus were higher in female fish than in male. Moreover, C. digitatus and C. dossoui were more concentrated in male than female whereas there was not a difference in infection of C. anthemocolpos, C. arthracanthus, C. yanni, C. lagoonaris, C.  louipaysani and C. kouassii based on the sex of Tilapia guineensis. This could enable the use of appropriate methods to fight against these pathogens, especially in intensive fish farming.

Keywords: Monogeneans, Tilapia guineensis, population dynamics, Lake Ayamé 2.