The Monogenean Parasite Fauna of Cichlids: A Potential Tool for Host Biogeography

We discuss geographical distribution and phylogeny of Dactylogyridea (Monogenea) parasitizing Cichlidae to elucidate their hosts' history. Although mesoparasitic Monogenea (Enterogyrus spp.) show typical vicariant distribution, ectoparasitic representatives from different continents are not considered sister taxa, hence their distribution cannot result from vicariance alone. Because of the close host-parasite relationship, this might indicate that present-day cichlid distribution may also reflect dispersal through coastal or brackish waters. Loss of ectoparasites during transoceanic migration, followed by lateral transfer from other fish families might explain extant host-parasite associations. Because of its mesoparasitic nature, hence not subject to salinity variations of the host's environment, Enterogyrus could have survived marine migrations, intolerable for ectoparasites. Host-switches and salinity transitions may be invoked to explain the pattern revealed by a preliminary morphological phylogeny of monogenean genera from Cichlidae and other selected Monogenea genera, rendering the parasite distribution explicable under both vicariance and dispersal. Testable hypotheses are put forward in this parasitological approach to cichlid biogeography. Along with more comprehensive in-depth morphological phylogeny, comparison with molecular data, clarifying dactylogyridean evolution on different continents and from various fish families, and providing temporal information on host-parasite history, are needed to discriminate between the possible scenarios

IN VITRO AMOEBICIDAL ACTIVITY OF SOME MEDICINAL PLANTS OF THE BAMUN REGION (CAMEROON)

Fifty two medicinal plants belonging to different families selected on the basis of their traditional use against jaundice and various liver disorders were tested for their amoebicidal activities. They were extracted and tested for their antiamoebic activity in vitro using polyxenic culture of Entamoebic histolytica. As the result, 14 exhibited an antiamoebic activity at a dose of 100µg/ml from the second to the fourth day of incubation. The 14 selected extracts were additionaly tested for 6 days at 10, 100 and 500g/ml of concentration, and only the leaves extract of Codiaeum variegatum exhibited a clear antiamoebic activity (EC50=10,74 the second day), and had a more pronounced activity than metronidazole the reference product

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

Description of three new species of Quadriacanthus (Monogenea: Ancyrocephalidae) gill parasites of Clarias submarginatus (Siluriformes: Clariidae) from Lake Ossa (Littoral region, Cameroon)

ABSTRACT Clariidae is a group that includes many species that have great economic importance in both fisheries and fish culture. Monogenean parasites of fishes assigned to this family have been studied in Cameroon, but there have been no studies on Clarias submarginatus Peter, 1882, a fish that is traditionally consumed by the local people. The examination of 43 specimens identified as C. submarginatus from Lake Ossa (first record of this fish species in the Sanaga basin), revealed that some of them belong to Quadriacanthus and are new. Their identification was made based on the morphology and the size of sclerotized parts of the haptor and the male and female copulatory complexes. Quadriacanthus macruncus Bahanak, Nack & Pariselle sp. nov. and Quadriacanthus submarginati Bahanak, Nack & Pariselle sp. nov. are characterized by the morphology of their accessory piece, pointed, slightly curved and wider at medium level, equipped with two subterminal, symmetrical and similar spines for Q. macruncus sp. nov. and made up of one long tip flanked by a short spine and a bulb for Q . submarginati sp. nov., while Quadriacanthus ossaensis Bahanak, Nack & Pariselle sp. nov. is distinguished by the unique morphology of the penis, ending in a fork. The new species of Quadriacanthus are herein described and their host specificity is discussed

Inventory and Ecological Characterization of Ichthyofauna of Nine Lakes in the Adamawa Region (Northern Cameroon, Central Africa)

The fish diversity of the Adamawa lakes is among the most undocumented in Northern Cameroon. Faced with this lack of knowledge, an inventory of ichthyofauna and habitats characterization was conducted in nine lakes. Seven lakes (Assom, Gegouba, Massote, Mbalang, Ngaoundaba, Piou and Tizong) are located in the Sanaga Basin and two (Bini and Dang) are located in the Lake Chad Basin. In order to assess the composition and variation in fish assemblage, eight sampling campaigns were carried out seasonally between 2017 and 2018; they revealed 26 species of fish distributed in 6 orders, 9 families and 16 genera. Communities in Lakes Assom (13 species) and Bini (9 species) were the most diverse. Omnivorous (42.3%) and spawners in open water or on substrates of sand, gravel, rock or plants (69.2%) were the most represented. Nonmetric multidimensional scaling, analysis of similarities (ANOSIM), and similarity percentage analysis (SIMPER) revealed that fish species composition differed significantly among lakes. Canonical correspondence analysis (CCA) identified temperature, pH, TDS, and conductivity as variables explaining the most variation in fish species. The presence of four endemic species in the Sanaga Basin in lakes Assom, Gegouba, Massote and Piou, shows that these lakes stand out as hotspots for conservation due to the uniqueness of their ichthyofauna

Description of three new species of Quadriacanthus (Monogenea: Ancyrocephalidae) gill parasites of Clarias submarginatus (Siluriformes: Clariidae) from Lake Ossa (Littoral region, Cameroon)

ABSTRACT Clariidae is a group that includes many species that have great economic importance in both fisheries and fish culture. Monogenean parasites of fishes assigned to this family have been studied in Cameroon, but there have been no studies on Clarias submarginatus Peter, 1882, a fish that is traditionally consumed by the local people. The examination of 43 specimens identified as C. submarginatus from Lake Ossa (first record of this fish species in the Sanaga basin), revealed that some of them belong to Quadriacanthus and are new. Their identification was made based on the morphology and the size of sclerotized parts of the haptor and the male and female copulatory complexes. Quadriacanthus macruncus Bahanak, Nack & Pariselle sp. nov. and Quadriacanthus submarginati Bahanak, Nack & Pariselle sp. nov. are characterized by the morphology of their accessory piece, pointed, slightly curved and wider at medium level, equipped with two subterminal, symmetrical and similar spines for Q. macruncus sp. nov. and made up of one long tip flanked by a short spine and a bulb for Q . submarginati sp. nov., while Quadriacanthus ossaensis Bahanak, Nack & Pariselle sp. nov. is distinguished by the unique morphology of the penis, ending in a fork. The new species of Quadriacanthus are herein described and their host specificity is discussed

New species of Synodontella (Monogenea, Ancyrocephalidae) gill parasites of two Synodontis spp. (Pisces, Mochokidae) from the Boumba River (Congo Basin, East Cameroon)

International audienceThree new species of Synodontella Dossou & Euzet, 1993 are described from two species of Synodontis (Mochokidae) collected from the middle course of the Boumba River (East Cameroon): Synodontella angustupenis n. sp. from Synodontis nummifer, Synodontella longipenis n. sp. and Synodontella simplex n. sp. from Synodontis decorus. These new species are different from the other Synodontella species already described due to their horseshoe-shaped dorsal transverse bars. Synodontella angustupenis differs from S. longipenis and S. simplex by the morphology of its penis, a thin tube, and its accessory piece, bifid at its extremity. Synodontella longipenis differs from the other two species by the morphology and the size of its male copulatory organ, which is very long. Synodontella simplex differs from S. angustupenis and S. longipenis by the shape of its penis, which is simple, and of its accessory piece, with a developed heel. The difference between the dorsal transverse bars of Synodontella species from the Sanaga River in Cameroon (and other localities in Africa), slightly curved, and those from the Boumba River, horseshoe-shaped, makes it possible to separate Synodontella species into two different subgroups. This difference can be explained by a long isolation period of the hosts, living in different river basins, followed by the divergence of the parasite populations (vicariant speciation)