Six new species of Cichlidogyrus Paperna, 1960 (Platyhelminthes: Monogenea) from the gills of cichlids (Teleostei: Cichliformes) from the Lomami River Basin (DRC: Middle Congo)

Background Monogenea van Beneden, 1858 is a group of parasitic flatworms, commonly found infecting bony fish. Several genera, such as Cichlidogyrus Paperna, 1960, are reported to include potential pathogenic species that can negatively impact aquaculture fish stocks. They can switch from introduced to native fish and vice versa. In Africa (and all over the world), fish species belonging to Cichlidae are often kept in aquaculture and represent a major source of food. Thus, research on the biodiversity and occurrence of monogenean species on these fish is of importance for aquaculture and conservation. The present study is a survey of the diversity of species of Cichlidogyrus in the south of the Democratic Republic of the Congo (DRC) on three cichlid species: Orthochromis sp. 'Lomami', Serranochromis cf. macrocephalus, and Tilapia sparrmanii Smith, 1840. Methods Specimens of Cichlidogyrus were isolated from the gills and mounted on glass slides with Hoyer's medium. The genital and haptoral hard parts were measured and drawn using interference contrast. Results In total, six species of Cichlidogyrus were found, all new to science: C. bulbophallus n. sp. and C. pseudozambezensis n. sp. on S. cf. macrocephalus, C. flagellum n. sp. and C. lobus n. sp. on T. sparrmanii, C. ranula n. sp. on S. cf. macrocephalus and Orthochromis sp. 'Lomami', and C. maeander n. sp. found on Orthochromis sp. 'Lomami' and T. sparrmanii. The first four species are considered to be strict specialists, C. ranula n. sp. an intermediate generalist and C. maeander n. sp. a generalist. These parasite species show morphological similarities to species found in the Lower Guinea and Zambezi ichthyofaunal provinces, which might be explained by past river capture events between river systems of the Congo Province and both these regions. Conclusions Serranochromis cf. macrocephalus and Orthochromis sp. 'Lomami' can harbour respectively three and two species of Cichlidogyrus, all described in this study. Tilapia sparrmanii can harbour seven species, of which three are described in the present study. These results highlight the species diversity of this parasite genus in the Congo Basin.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

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

Evolutionary genetics of the catfish Clarias gariepinus in the Congo Basin

The Congo Basin features among the oldest, largest and biologically richest on earth after the Amazon and before the Mekong. Sadly enough it is the least known. It offers opportunities to study evolution given its treasure of global biodiversity and high aquaculture potential (large hydrographic network and suitable climate). It is within this framework that phylogeographical research has been initiated to understand the origin of the ichthyological fauna and to identify potential strains for the development of aquaculture. The model chosen is the catfish Clarias gariepinus (Burchell, 1822), a species with great aquaculture potential. This fish lives in the Congo River from source to mouth, as well over a large part of the African continent. The results show the presence of four clades and several groups which represent a large genetic differentiation. Evolution is ancestral in the south and north of the Congo Basin (relict population) and represents a Pleistocene colonisation in the Central Basin. Even in a contemporary context, evolution seems to follow these two models. Two hypotheses have been retained to support the causes for the accumulation of diversity: the hypothesis of long-distance dispersal in the Central Basin and the refuge hypothesis in the peripheral zones of the Central Basin. Moreover, the four major clades have been identified to match with four major ichthyological provinces of Africa: Nilo-Sudan, Zambezi, East Coast and Congo. This confirms an ancient connection between the various basins. Hence, the evolution of C. gariepinus in the Congo basin corresponds with that of the fishes and mammals with a high dispersal capacity, which is found in several African basins. Ideally the evolution of the endemic fauna of the Congo basin should be studied in order to compare it with the higher mentioned high dispersal group. It would facilitate our understanding of the evolution of the fish fauna of this large African basin for sustainable management.Le bassin du Congo est l’un des plus vieux, vastes et biologiquement riches au monde après celui de l’Amazone et avant celui du Mekong. Malheureusement ce bassin est le moins connu. En tant que réserve de la biodiversité mondiale et ayant un potentiel aquacole élevé (grand réseau hydrographique et bon climat), ce bassin offre des opportunités d’études d’évolution. C’est dans ce cadre que des études phylogéographiques ont été initiées afin de connaître l’origine de la faune ichthyologique. Le modèle retenu était celui du poisson chat Clarias gariepinus (Burchell, 1822). Ce poisson est signalé dans le fleuve Congo de la source à l’embouchure, ainsi que dans la plus grande partie du continent africain. Les résultats obtenus ont révélé l’existence de cinq clades (groupements historiques de populations) dont quatre rencontré dans le bassin du Congo et plusieurs groupes présentant une grande différentiation génétique. Une évolution ancestrale (relique) caractérise le sud et le nord du bassin congolais; par contre dans la Cuvette Centrale on observe une colonisation récente. Même dans un contexte contemporain, l’évolution semble suivre les deux modèles. Deux hypothèses ont été retenues pour soutenir les causes de l’accumulation de la diversité. Il s’agit de l’hypothèse sur la longue distance de dispersion dans la Cuvette Centrale et celle des refuges dans les régions périphériques de la Cuvette Centrale. En plus, les quatre clades principaux ont été identifiés comme couvrant les quatre principales provinces ichthyologiques d’Afrique: Nilo-Soudanique, Zambèze, Côte Est et Congo. Ceci confirme l’ancienne connexion entre les différents bassins. Ainsi, l’évolution du C. gariepinus dans le bassin du Congo correspond à celle des poissons et mammifères à grande dispersion rencontrés dans plusieurs bassins africains. L’idéal serait d’étudier aussi l’évolution de la faune endémique du bassin congolais afin de la comparer avec celle appartenant au premier groupe (grande dispersion). Cla facilitera la compréhension de l’évolution de la faune ichtyologique de ce grand bassin d’Afrique pour un but de gestion durable.(DOCSC03) -- FUNDP, 201

Evaluation de la contamination de la chaïne trophique par les éléments traces (Cu, Co, Zn, Pb, Cd, U, V et As) dans le bassin de la Lufira supérieure (Katanga/RD Congo)

Evaluation of Contamination of the Food Chain by Trace Elements (Cu, Co, Zn, Pb, Cd, U, V and As) in the Basin of the Upper Lufira (Katanga/DR Congo). Seven trace elements (Cu, Co, Zn, Cd, Pb, U, V and As) were analyzed using a HR ICP-MS in samples of water, plankton, leaves of Phragmites australis, muscle and gills of three fish species (Oreochromis macrochir, Tilapia rendalli, Clarias gariepinus) collected in the basin of the upper Lufira. The results indicate a high copper (70.9 ppm) and cobalt (32.3 ppm) content in the effluent of complex hydrometallurgical Shituru. If contamination of rivers decreases with distance from the pollution source, the values are very high in lake Tshangalele for plankton and leaves of P. australis. For fish, the results indicate that Pb, U, V, Cu, Co and Cd accumulates preferentially in the gills but Zn accumulates more in the muscles. As accumulates in the same order of magnitude in both organs. These results confirm the pollution of the basin by the effluents from Lufira complex hydrometallurgical Shituru

FIGURE 8 in Description of five new rheophilic Orthochromis species (Teleostei: Cichlidae) from the Upper Congo drainage in Zambia and the Democratic Republic of the Congo

FIGURE 8. Type localities of the five newly described species A. Type locality of Orthochromis mporokoso, Kasinsha stream (July 2011, Hans van Heusden) B. Type locality of Orthochromis katumbii, Kiswishi River (2015, VLIR expedition) C. Type locality of Orthochromis gecki, Lubudi River (July 2017, Katanga 2016 Expedition) D. Type locality of Orthochromis kimpala, Kalule North River near bridge on the road Makulakulu-Lubudi (2012, PRODEPAAK expedition) E. Type locality of Orthochromis indermauri, Lufubu River at Chomba village (August 2015, photo F. Schedel)

Description of five new rheophilic Orthochromis species (Teleostei: Cichlidae) from the Upper Congo drainage in Zambia and the Democratic Republic of the Congo

Schedel, Frederic Dieter Benedikt, Vreven, Emmanuel J.W.M.N., Manda, Bauchet Katemo, Abwe, Emmanuel, Manda, Auguste Chocha, Schliewen, Ulrich Kurt (2018): Description of five new rheophilic Orthochromis species (Teleostei: Cichlidae) from the Upper Congo drainage in Zambia and the Democratic Republic of the Congo. Zootaxa 4461 (3): 301-349, DOI: https://doi.org/10.11646/zootaxa.4461.3.

Six new species of Cichlidogyrus Paperna, 1960 (Platyhelminthes: Monogenea) from the gills of cichlids (Teleostei: Cichliformes) from the Lomami River Basin (DRC: Middle Congo)

BACKGROUND: Monogenea van Beneden, 1858 is a group of parasitic flatworms, commonly found infecting bony fish. Several genera, such as Cichlidogyrus Paperna, 1960, are reported to include potential pathogenic species that can negatively impact aquaculture fish stocks. They can switch from introduced to native fish and vice versa. In Africa (and all over the world), fish species belonging to Cichlidae are often kept in aquaculture and represent a major source of food. Thus, research on the biodiversity and occurrence of monogenean species on these fish is of importance for aquaculture and conservation. The present study is a survey of the diversity of species of Cichlidogyrus in the south of the Democratic Republic of the Congo (DRC) on three cichlid species: Orthochromis sp. 'Lomami', Serranochromis cf. macrocephalus, and Tilapia sparrmanii Smith, 1840. METHODS: Specimens of Cichlidogyrus were isolated from the gills and mounted on glass slides with Hoyer's medium. The genital and haptoral hard parts were measured and drawn using interference contrast. RESULTS: In total, six species of Cichlidogyrus were found, all new to science: C. bulbophallus n. sp. and C. pseudozambezensis n. sp. on S. cf. macrocephalus, C. flagellum n. sp. and C. lobus n. sp. on T. sparrmanii, C. ranula n. sp. on S. cf. macrocephalus and Orthochromis sp. 'Lomami', and C. maeander n. sp. found on Orthochromis sp. 'Lomami' and T. sparrmanii. The first four species are considered to be strict specialists, C. ranula n. sp. an intermediate generalist and C. maeander n. sp. a generalist. These parasite species show morphological similarities to species found in the Lower Guinea and Zambezi ichthyofaunal provinces, which might be explained by past river capture events between river systems of the Congo Province and both these regions. CONCLUSIONS: Serranochromis cf. macrocephalus and Orthochromis sp. 'Lomami' can harbour respectively three and two species of Cichlidogyrus, all described in this study. Tilapia sparrmanii can harbour seven species, of which three are described in the present study. These results highlight the species diversity of this parasite genus in the Congo Basin.status: publishe

Diversity and host-specificity of monogenean gill parasites (Platyhelminthes) of cichlid fishes in the Bangweulu-Mweru ecoregion

This study represents the first exploration of the parasite fauna of cichlid fishes in the Mweru-Luapula subregion (Central Africa). Twelve species of cichlids and 14 species of Monogenea from three genera (Cichlidogyrus, Gyrodactylus and Scutogyrus) were collected. We present a first record of the gill parasite fauna of eight host species, Oreochromis mweruensis, Orthochromis sp. 'Mambilima', Sargochromis mellandi, Serranochromis angusticeps, S. stappersi, S. thumbergi and Tylochromis mylodon. The host range of ten parasite species was expanded. The study further includes the description of Cichlidogyrus consobrini sp. n. from S. mellandi and Orthochromis sp. 'Mambilima'. A new morphotype of C. halli is characterized, and three species - C. papernastrema, C. quaestio and C. zambezensis - are redescribed. Furthermore, the biodiversity and host specificity of these parasites is compared with that of cichlid parasites from Lake Kariba and Cameroon. Two species, including C. consobrini sp. n. and a new morphotype of C. halli, are putative endemics. The parasite fauna in Bangweulu-Mweru is highly similar in species composition to Lake Kariba, but in Bangweulu-Mweru the same parasite species are more host-specific, probably because of hydrogeographical differences between the two regions.status: publishe