Mosaic or melting pot : The use of monogeneans as a biological tag and magnifying glass to discriminate introduced populations of Nile tilapia in sub-Saharan Africa

The origin of introduced Nile tilapia stocks in sub-Saharan Africa is largely unknown. In this study, the potential of monogeneans as a biological tag and magnifying glass is tested to reveal their hosts' stocking history. The monogenean gill community of different Nile tilapia populations in sub-Saharan Africa was explored, and a phylogeographic analysis was performed based on the mitogenomes of four dactylogyrid species (Cichlidogyrus hani, C. sclerosus, C. thurstonae, and Scutogyrus longicornis). Our results encourage the use of dactylogyrids as biological tags. The magnifying glass hypothesis is only confirmed for C. thurstonae, highlighting the importance of the absence of other potential hosts as prerequisites for a parasite to act as a magnifying glass. With the data generated here, we are the first to extract mitogenomes from individual monogeneans and to perform an upscaled survey of the comparative phylogeography of several monogenean species with unprecedented diagnostic resolution.Peer reviewe

Mosaic or melting pot : The use of monogeneans as a biological tag and magnifying glass to discriminate introduced populations of Nile tilapia in sub-Saharan Africa

The origin of introduced Nile tilapia stocks in sub-Saharan Africa is largely unknown. In this study, the potential of monogeneans as a biological tag and magnifying glass is tested to reveal their hosts' stocking history. The monogenean gill community of different Nile tilapia populations in sub-Saharan Africa was explored, and a phylogeographic analysis was performed based on the mitogenomes of four dactylogyrid species (Cichlidogyrus hani, C. sclerosus, C. thurstonae, and Scutogyrus longicornis). Our results encourage the use of dactylogyrids as biological tags. The magnifying glass hypothesis is only confirmed for C. thurstonae, highlighting the importance of the absence of other potential hosts as prerequisites for a parasite to act as a magnifying glass. With the data generated here, we are the first to extract mitogenomes from individual monogeneans and to perform an upscaled survey of the comparative phylogeography of several monogenean species with unprecedented diagnostic resolution.Peer reviewe

Ancyrocephalidae (Monogenea) of Lake Tanganyika. IV. Cichlidogyrus parasitizing species of Bathybatini (Teleostei, Cichlidae) : reduced host-specificity in the deepwater realm ?

Lake Tanganyika's biodiversity and endemicity sparked considerable scientific interest. Its monogeneans, minute parasitic flatworms, have received renewed attention. Their host-specificity and simple life cycle render them ideal for parasite speciation research. Because of the wide ecological and phylogenetic range of its cichlids, Lake Tanganyika is a "natural experiment" to contrast factors influencing monogenean speciation. Three representatives of Bathybatini (Bathybates minor, B. fasciatus, B. vittatus), endemic predatory non-littoral cichlids, host a single dactylogyridean monogenean species. It is new to science and described as Cichlidogyrus casuarinus sp. nov. This species and C. nshomboi and C. centesimus, from which it differs by the distal end of the accessory piece of the male apparatus and the length of its heel, are the only Cichlidogyrus species with spirally coiled thickening of the penis wall. In Cichlidogyrus, this feature was only found in parasites of endemic Tanganyika tribes. The seemingly speciespoor Cichlidogyrus community of Bathybatini may be attributed to meagre host isolation in open water. The new species infects cichlids that substantially differ phylogenetically and ecologically. This may be an adaptation to low host availability. Cichlidogyrus species infecting African Great Lake cichlids are summarized and proposed as model for the influence of host ecology on disease transmission