Congo Basin Dotaz Zobrazit nápovědu
The Lower Congo Basin is characterized by a mangrove-lined estuary at its mouth and, further upstream, by many hydrogeographical barriers such as rapids and narrow gorges. Five localities in the mangroves and four from (upstream) left bank tributaries or pools were sampled. On the gills of Coptodon tholloni, Coptodon rendalli, Hemichromis elongatus, Hemichromis stellifer and Tylochromis praecox, 17 species of parasites (Dactylogyridae & Gyrodactylidae, Monogenea) were found, eight of which are new to science. Six of these are herein described: Cichlidogyrus bixlerzavalai n. sp. and Cichlidogyrus omari n. sp. from T. praecox, Cichlidogyrus calycinus n. sp. and Cichlidogyrus polyenso n. sp. from H. elongatus, Cichlidogyrus kmentovae n. sp. from H. stellifer and Onchobdella ximenae n. sp. from both species of Hemichromis. On Cichlidogyrus reversati a ridge on the accessory piece was discovered that connects to the basal bulb of the penis. We report a putative spillback effect of the native parasites Cichlidogyrus berradae, Cichlidogyrus cubitus and Cichlidogyrus flexicolpos from C. tholloni to the introduced C. rendalli. From our results, we note that the parasite fauna of Lower Congo has a higher affinity with the fauna of West African and nearby freshwater ecoregions than it has with fauna of other regions of the Congo Basin and Central Africa.
- MeSH
- biodiverzita MeSH
- cichlidy anatomie a histologie parazitologie MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- infekce červy třídy Trematoda epidemiologie parazitologie veterinární MeSH
- nemoci ryb epidemiologie parazitologie MeSH
- ploštěnci klasifikace genetika izolace a purifikace MeSH
- sladká voda parazitologie MeSH
- žábry parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Kongo MeSH
- MeSH
- demografie MeSH
- druhová specificita MeSH
- hadi anatomie a histologie klasifikace fyziologie MeSH
- řeky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- dopisy MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Konžská demokratická republika MeSH
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.
- MeSH
- biodiverzita MeSH
- cichlidy parazitologie MeSH
- fylogeneze MeSH
- klasifikace * MeSH
- koinfekce parazitologie MeSH
- nemoci ryb parazitologie MeSH
- řeky parazitologie MeSH
- rybí výrobky parazitologie MeSH
- ryby MeSH
- Tilapia parazitologie MeSH
- Trematoda anatomie a histologie klasifikace izolace a purifikace MeSH
- vodní hospodářství MeSH
- žábry parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Chad Basin, lying within the bidirectional corridor of African Sahel, is one of the most populated places in Sub-Saharan Africa today. The origin of its settlement appears connected with Holocene climatic ameliorations (aquatic resources) that started ~10,000 years before present (YBP). Although both Nilo-Saharan and Niger-Congo language families are encountered here, the most diversified group is the Chadic branch belonging to the Afro-Asiatic language phylum. In this article, we investigate the proposed ancient migration of Chadic pastoralists from Eastern Africa based on linguistic data and test for genetic traces of this migration in extant Chadic speaking populations.
- MeSH
- emigrace a imigrace MeSH
- financování organizované MeSH
- fylogeneze MeSH
- genetická variace MeSH
- haplotypy genetika MeSH
- jazyk (prostředek komunikace) MeSH
- lidé MeSH
- mitochondriální DNA genetika MeSH
- populační genetika MeSH
- zeměpis MeSH
- Check Tag
- lidé MeSH
- Geografické názvy
- Afrika MeSH
- Čad MeSH
Twenty species (sixteen adult and four larval) of parasitic nematodes belonging to the Ascaridoidea, Camallanoidea, Cosmocercoidea, Dioctophymatoidea, Habronematoidea, Oxyuroidea, Seuratoidea, and Thelazioidea were collected from freshwater fishes of the Congo River basin in the Democratic Republic of the Congo and the Central African Republic in 2008 and 2012, respectively. Based on light and scanning electron microscopical examination, many species are redescribed in detail. This material also contained four previously unknown species, Labeonema longispiculatum sp. n. from Synodontis acanthomias Boulenger, Gendria longispiculata sp. n. from Schilbe grenfelli (Boulenger), G. sanghaensis sp. n. from Schilbe marmoratus Boulenger, and Cucullanus congolensis sp. n. from Auchenoglanis occidentalis (Valenciennes). The new species L. longispiculatum is mainly characterised by conspicuously long (210-228 µm) spicules, approximately twice as long as those in other congeners, the length (45-48 µm) of the gubernaculum and the host family (Mochokidae), whereas G. longispiculata by very long (1.2 mm) spicules, the shape of the oesophagus and cephalic vesicle, distribution of postanal papillae and the host family (Schilbeidae). Main characteristic features of G. sanghaensis are the presence of a hexagonal oral aperture surrounded by lip-like structures, the posterior portion of the oesophagus moderately expanded, spicules and the gubernaculum 414-438 µm and 54-57 µm long, respectively, deirids located at the level of the posterior end of the oesophagus and the absence of cervical alae. Cucullanus congolensis differs from congeneric species parasitising African freshwater and brackish-water fishes mainly in the absence of a ventral precloacal sucker and lateral preanal papillae, the presence of a large median precloacal papilla-like formation, spicules 480-489 µm long and the location of the excretory pore in the region of the oesophago-intestinal junction. Chabaudus Inglis et Ogden, 1965 is considered a junior synonym of Gendria Baylis, 1930 and, consequently, species listed in the former genus are transferred to the latter as G. alaini (Alfonso-Roque, 1981) comb. n., G. chabaudi (Inglis et Ogden, 1965) comb. n., G. dehradunensis (Rizvi, Bursey et Maity, 2016) comb. n., G. thysi (Puylaert, 1970) comb. n. and G. williamsi (Puylaert, 1970) comb. n. The findings represent many new host and geographical records.
- MeSH
- hlístice klasifikace ultrastruktura MeSH
- mikroskopie elektronová rastrovací veterinární MeSH
- nematodózy parazitologie veterinární MeSH
- nemoci ryb parazitologie MeSH
- řeky MeSH
- ryby MeSH
- sladká voda parazitologie MeSH
- střeva parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Konžská demokratická republika MeSH
- Středoafrická republika MeSH
The flatworms of the genus Cichlidogyrus Paperna, 1960 (Monogenea: Ancyrocephalidae) are gill parasites of freshwater fish, affecting predominantly the family Cichlidae. Cichlidogyrus tiberianus Paperna, 1960 and Cichlidogyrus dossoui Douëllou, 1993 are among the most widely distributed species of the genus, occurring in several African river basins and infecting many different host species, including the economically important Nile tilapia Oreochromis niloticus (Linnaeus) and redbreast tilapia Coptodon rendalli (Boulenger). Despite their wide distribution, C. tiberianus and C. dossoui have so far been studied only by light microscopy. In this paper they are redescribed on the basis of scanning electron microscopy of newly-collected material. The new material was obtained from redbreast tilapia caught in the Luapula River (D. R. Congo). The haptoral sclerites and genitalia are redescribed and illustrated in detail. Special attention is given to the complex morphology of the male copulatory organ.
- MeSH
- druhová specificita MeSH
- mikroskopie elektronová rastrovací MeSH
- mužské pohlavní orgány ultrastruktura MeSH
- Tilapia parazitologie MeSH
- Trematoda klasifikace izolace a purifikace ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Kongo MeSH
BACKGROUND: Cichlids are a prime model system in evolutionary research and several of the most prominent examples of adaptive radiations are found in the East African Lakes Tanganyika, Malawi and Victoria, all part of the East African cichlid radiation (EAR). In the past, great effort has been invested in reconstructing the evolutionary and biogeographic history of cichlids (Teleostei: Cichlidae). In this study, we present new divergence age estimates for the major cichlid lineages with the main focus on the EAR based on a dataset encompassing representative taxa of almost all recognized cichlid tribes and ten mitochondrial protein genes. We have thoroughly re-evaluated both fossil and geological calibration points, and we included the recently described fossil †Tugenchromis pickfordi in the cichlid divergence age estimates. RESULTS: Our results estimate the origin of the EAR to Late Eocene/Early Oligocene (28.71 Ma; 95% HPD: 24.43-33.15 Ma). More importantly divergence ages of the most recent common ancestor (MRCA) of several Tanganyika cichlid tribes were estimated to be substantially older than the oldest estimated maximum age of the Lake Tanganyika: Trematocarini (16.13 Ma, 95% HPD: 11.89-20.46 Ma), Bathybatini (20.62 Ma, 95% HPD: 16.88-25.34 Ma), Lamprologini (15.27 Ma; 95% HPD: 12.23-18.49 Ma). The divergence age of the crown haplochromine H-lineage is estimated to 22.8 Ma (95% HPD: 14.40-26.32 Ma) and of the Lake Malawi radiation to 4.07 Ma (95% HDP: 2.93-5.26 Ma). In addition, we recovered a novel lineage within the Lamprologini tribe encompassing only Lamprologus of the lower and central Congo drainage with its divergence estimated to the Late Miocene or early Pliocene. Furthermore we recovered two novel mitochondrial haplotype lineages within the Haplochromini tribe: 'Orthochromis' indermauri and 'Haplochormis' vanheusdeni. CONCLUSIONS: Divergence time estimates of the MRCA of several Tanganyika cichlid tribes predate the age of the extant Lake Tanganyika basin, and hence are in line with the recently formulated "Melting-Pot Tanganyika" hypothesis. The radiation of the 'Lower Congo Lamprologus clade' might be linked with the Pliocene origin of the modern lower Congo rapids as has been shown for other Lower Congo cichlid assemblages. Finally, the age of origin of the Lake Malawi cichlid flock agrees well with the oldest age estimate for lacustrine conditions in Lake Malawi.
- MeSH
- biologická evoluce * MeSH
- časové faktory MeSH
- cichlidy klasifikace genetika MeSH
- fylogeneze MeSH
- genetická variace * MeSH
- jezera * MeSH
- kalibrace MeSH
- mitochondriální DNA genetika MeSH
- mitochondriální geny MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Kongo MeSH
- Tanzanie MeSH
Organismal traits interact with environmental variation to mediate how species respond to shared landscapes. Thus, differences in traits related to dispersal ability or physiological tolerance may result in phylogeographic discordance among co-distributed taxa, even when they are responding to common barriers. We quantified climatic suitability and stability, and phylogeographic divergence within three reed frog species complexes across the Guineo-Congolian forests and Gulf of Guinea archipelago of Central Africa to investigate how they responded to a shared climatic and geological history. Our species-specific estimates of climatic suitability through time are consistent with temporal and spatial heterogeneity in diversification among the species complexes, indicating that differences in ecological breadth may partly explain these idiosyncratic patterns. Likewise, we demonstrated that fluctuating sea levels periodically exposed a land bridge connecting Bioko Island with the mainland Guineo-Congolian forest and that habitats across the exposed land bridge likely enabled dispersal in some species, but not in others. We did not find evidence that rivers are biogeographic barriers across any of the species complexes. Despite marked differences in the geographic extent of stable climates and temporal estimates of divergence among the species complexes, we recovered a shared pattern of intermittent climatic suitability with recent population connectivity and demographic expansion across the Congo Basin. This pattern supports the hypothesis that genetic exchange across the Congo Basin during humid periods, followed by vicariance during arid periods, has shaped regional diversity. Finally, we identified many distinct lineages among our focal taxa, some of which may reflect incipient or unrecognized species.
- MeSH
- biologická evoluce * MeSH
- biologické modely MeSH
- buněčné jádro genetika MeSH
- fenotyp MeSH
- fylogeneze * MeSH
- fylogeografie MeSH
- klimatické změny * MeSH
- lesy * MeSH
- mitochondriální DNA genetika MeSH
- ostrovy MeSH
- žáby klasifikace MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Guinea MeSH
- ostrovy MeSH
- střední Afrika MeSH
The headwaters of five large African river basins flow through the Bié Plateau in Angola and still remain faunistically largely unexplored. We investigated fish fauna from the Cuanza and Okavango-Zambezi river systems from central Angola. We reconstructed molecular phylogenies of the most common cichlid species from the region, Tilapia sparrmanii and Serranochromis macrocephalus, using both mitochondrial and nuclear markers. We found evidence for ichthyofaunal contact and gene flow between the Cuanza and Okavango-Zambezi watersheds in the Bié Plateau in central Angola. Waterfalls and rapids also appeared to restrict genetic exchange among populations within the Cuanza basin. Further, we found that the Angolan Serranochromis cichlid fishes represent a monophyletic lineage with respect to other haplochromines, including the serranochromines from the Congo and Zambezi rivers. This study represents an important initial step in a biodiversity survey of this extremely poorly explored region, as well as giving further understanding to species distributions and gene flow both between and within river basins.
- MeSH
- cichlidy klasifikace genetika MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- mitochondriální DNA MeSH
- molekulární evoluce MeSH
- molekulární sekvence - údaje MeSH
- řeky * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Angola MeSH
A new nematode species, Dujardinascaris mormyropsis n. sp. (Anisakidae), is described from specimens found in the stomach and intestine of the cornish jack Mormyrops anguilloides (Linnaeus) (Osteoglossiformes; Mormyridae) in the Sangha River (Congo River basin) in Dzanga-Sangha Protected Areas, Central African Republic. Based on light and scanning electron microscopical examination, the new species differs from the only other congeneric species parasitising fishes in Africa, D. malapteruri (Baylis, 1923), mainly in the presence of dentigerous ridges on lips, absence of lateral caudal alae in the cloacal region, in the anteriorly curved, non-bifid distal tip of the gubernaculum and larger eggs (60-90 × 52-78 vs 45 × 30 μm); males of D. mormyropsis are characterised by the presence of a ventral precloacal cuticular ornamentation not observed in other Dujardinascaris spp. Dujardinascaris mormyropsis and D. malapteruri also differ in the order of their fish hosts (Osteoglossiformes vs Siluriformes). Specimens previously reported as Dujardinascaris graberi Troncy, 1969, a junior synonym of D. malapteruri, from Mormyrops engystoma Boulenger in Chad belong to the new species D. mormyropsis.
- MeSH
- Ascaridoidea klasifikace cytologie ultrastruktura MeSH
- druhová specificita MeSH
- elektrické ryby parazitologie MeSH
- infekce hlísticemi řádu Ascaridida parazitologie veterinární MeSH
- střeva parazitologie MeSH
- žaludek parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- střední Afrika MeSH