Publication details
Diversity and phylogeny of parasitic crustaceans on cichlids from Lake Tanganyika
| Authors | |
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| Year of publication | 2022 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Parasitic crustaceans infect fish communitites practically all around the world and represent very diverse, but in many places nowadays neglected group of organisms. It is not any different in Lake Tanganyika, the deepest and the oldest lake in Africa. This water body is an unique freshwater ecosystem characterized by high levels of species richness and high degree of endemism. Therefore, it received intensive interest from scientists in various fields of research since its discovery, even for parasitic crustaceans. However, many decades have passed since last systematic studies, which would be concerned with these parasites in this area of the world. Work of previous researchers produced morphological descriptions of parasitic crustaceans of family Ergasilidae in Africa, but without any molecular approach. The genus Ergasilus, von Nordmann, 1832 represents the species-rich group of parasitic copepods of family Ergasilidae, with approximately 180 species described worldwide. In Africa, 11 species of Ergasilus are known from freshwater fishes, four of them have been recorded in Lake Tanganyika: E. flaccidus Fryer, 1965, E. kandti van Douwe, 1912, E. megacheir (Sars, 1909) and E. sarsi Capart 1944. The fifth one, E. macrodactylus (Sars, 1909), had an unclear status so far. We investigated in our field study fish hosts belonging to Cichlidae family, which represents one of the most species-rich families of vertebrates. The East African Great Lakes are home to more than 1500 endemic species, 250 of them occurs in Lake Tanganyika and belong to more then 50 genera and 13 tribes. In recent years, cichlid fishes became also a suitable model for studies of host-parasite systems. The main goal of this study was to provide the taxonomic update of Ergasilus species parasitizing cichlid fishes collected during an expedition in Lake Tanganyika, more specifically along Burundese shorelines in 2013. There were 170 cichlids examined, belonging to 23 distinct species and 11 tribes. Overall, 1265 parasites of family Ergasilidae were found, and they were determined into five different species, using morphological and molecular methods. For the molecular analysis, two genetic markers (28S rDNA and 18S rDNA) were used and the very first sequences for Ergasilus genus in Africa were obtained. After more than 50 years, the presence of E. megacheir was reconfirmed in the studied system and the occurrence of E. macrodactylus in the Lake cleared up. Three other species were considered new for science. Newly obtained sequences from the Lake Tanganyika create a cluster separated from Asian species that were processed by previous authors, more data from Africa is still needed. We discussed the approach to study parasitic crustaceans up to now and suggested needed revision of the whole group in the near future, mainly with application of both morphological and molecular methods. |