SPECIES DIVERSITY OF CICHLIDOGYRUS (DACTYLOGYRIDAE) PARASITES OF TANGANYIKAN CICHLIDS: IT IS JUST BEGINNING … AND CONTINUES

Cichlids are one of the most species-rich families of vertebrates. Lake Tanganyika, the deepest and oldest lake in Africa, counts the most genetically, morphologically and ecologically diverse cichlid assemblage of African lakes and holds about 250 endemic species belonging to more than fifty genera and 14 to 16 tribes. Its mostly endemic cichlids are considered as a model to study biological diversification and radiation. Tanganyikan cichlids were started to be investigated for their gill ectoparasites during a few last years. Our results seem to confirm that species richness of cichlid parasites in Lake Tanganyika is higher than the number of cichlid species in this lake. Based on our knowledge on freshwater fish monogeneans, the taxonomy of Cichlidogyrus will remain, just as their hosts’ systematics is frequently revised, a subject of frequent revision. Thus, phylogenetic analysis based on molecular data are increasingly used to understand the cichlids’ diversity, evolution and host-parasite interactions. In addition, morphological characterization of the sclerotized structures (haptor and copulatory organs) represents another potential tool to investigate cichlid diversity. The main goal of this study is to investigate the Cichlidogyrus diversity of five Burundese cichlid hosts: Aulonocranus dewindti and Ophthalmotilapia nasuta from the tribe Ectodini, Eretmodus marksmithi and Tanganicodus irsacae from Eretmodini and finally Cyprichromis microlepidotus from Cyprichromini. Two approaches were employed: phylogenetics using different molecular markers (28S rDNA, 18S rDNA, ITS-1 and COX1) and morphological characterization of the hard parts of haptor and reproductive organs. Based on preliminary results, we suggest that phylogenetic relationships among Cichlidogyrus parasitizing the different Tanganyikan cichlid tribes may help us to elucidate the historic and ecological associations between cichlid tribes and to determine the origin of their monogeneans.