scholarly journals Back to Tanganyika: a case of recent trans-species-flock dispersal in East African haplochromine cichlid fishes

2015 ◽  
Vol 2 (3) ◽  
pp. 140498 ◽  
Author(s):  
Britta S. Meyer ◽  
Adrian Indermaur ◽  
Xenia Ehrensperger ◽  
Bernd Egger ◽  
Gaspard Banyankimbona ◽  
...  
Keyword(s):  
Lake Tanganyika ◽  
Lake Victoria ◽  
Species Flock ◽  
East African ◽  
Cichlid Species ◽  
African Great Lakes ◽  
Cichlid Fishes ◽  
Haplochromine Cichlid ◽  
Lake Victoria Region ◽  
Adaptive Radiations

The species flocks of cichlid fishes in the East African Great Lakes are the largest vertebrate adaptive radiations in the world and illustrious textbook examples of convergent evolution between independent species assemblages. Although recent studies suggest some degrees of genetic exchange between riverine taxa and the lake faunas, not a single cichlid species is known from Lakes Tanganyika, Malawi and Victoria that is derived from the radiation associated with another of these lakes. Here, we report the discovery of a haplochromine cichlid species in Lake Tanganyika, which belongs genetically to the species flock of haplochromines of the Lake Victoria region. The new species colonized Lake Tanganyika only recently, suggesting that faunal exchange across watersheds and, hence, between isolated ichthyofaunas, is more common than previously thought.

scholarly journals Phylogeny of the Lake Tanganyika Cichlid Species Flock and Its Relationship to the Central and East African Haplochromine Cichlid Fish Faunas

2002 ◽  
Vol 51 (1) ◽  
pp. 113-135 ◽  
Author(s):  
Walter Salzburger ◽  
Axel Meyer ◽  
Sanja Baric ◽  
Erik Verheyen ◽  
Christian Sturmbauer
Keyword(s):  
Lake Tanganyika ◽  
Cichlid Fish ◽  
Species Flock ◽  
East African ◽  
Cichlid Species ◽  
Haplochromine Cichlid

scholarly journals Four new species of Cichlidogyrus (Platyhelminthes, Monogenea, Dactylogyridae) from Lake Victoria haplochromine cichlid fishes, with the redescription of C. bifurcatus and C. longipenis

2021 ◽  
Author(s):  
Tiziana P Gobbin ◽  
Maarten PM Vanhove ◽  
Ole Seehausen ◽  
Martine E Maan ◽  
Antoine Pariselle
Keyword(s):  
Nous Avons ◽  
Host Specificity ◽  
Lake Victoria ◽  
Model Systems ◽  
Zoological Nomenclature ◽  
Cichlid Species ◽  
African Great Lakes ◽  
Adaptive Radiations ◽  
African Cichlids ◽  
Host Parasite

AbstractAfrican cichlids are model systems for evolutionary studies and for host-parasite interactions, because of their adaptive radiations and because they harbour many species of monogenean parasites with high host-specificity. Here, we sampled five locations in southern Lake Victoria, the youngest of the African Great Lakes. We surveyed gillinfecting monogeneans from 18 cichlid species belonging to the Lake Victoria radiation superflock and two cichlid species representing two older and distantly related lineages. We found one species of Gyrodactylus (Gyrodactylidae, Monogenea), Gyrodactylus sturmbaueri Vanhove, Snoeks, Volckaert & Huyse, 2011, and seven species of Cichlidogyrus (Dactylogyridae, Monogenea). Four species are herein described: Cichlidogyrus pseudodossoui n. sp., C. nyanza n. sp., C. furu n. sp., C. vetusmolendarius n. sp.. Another species is reported but not formally described (because of few specimens and morphological similarity with C. furu n. sp.). Two other species are redescribed: Cichlidogyrus bifurcatus Paperna, 1960 and C. longipenis Paperna & Thurston, 1969. Our results confirm that the monogenean fauna of Victorian littoral cichlids displays lower species richness and lower host-specificity than that of Lake Tanganyika littoral cichlids. In C. furu n. sp., hooks V are clearly longer than the other hooks, highlighting the need to re-evaluate the current classification system of haptoral configurations that considers hook pairs III-VII as rather uniform. Some morphological features of C. bifurcatus, C. longipenis and C. nyanza n. sp. suggest that these are closely related to other congeners that infect haplochromines. We also found morphological indications that representatives of Cichlidogyrus colonised Lake Victoria haplochromines or their ancestors at least twice, which is in line with the Lake Victoria superflock being colonized by two cichlid tribes (Haplochromini and Oreochromini).DisclaimerThis preprint is disclaimed for purposes of Zoological Nomenclature in accordance with the International Code of Zoological Nomenclature, Fourth Edition Articles 8.2 and 8.3 (ICZN 1999). No new names or nomenclatural changes are available from statements in this preprint.Résumé - Quatre espèces nouvelles de Cichlidogyrus (Platyhelminthes, Monogenea, Dactylogyridae) parasites d’haplochrominé (Cichlidae) du lac Victoria, avec la redescription de C. bifurcatus and C. longipenisA cause des radiations adaptatives qu’ils ont subies, les cichlidés africain sont des systèmes modèles pour étudier l’évolution, mais aussi les relations hôtes/parasites, car ils hébergent de nombreuses espèces de Monogènes parasites qui présentent une spécificité étroite vis-à-vis de leurs hôtes. Dans ce travail, nous avons échantillonné cinq localités dans le Sud du lac Victoria, le plus jeune des grands lacs d’Afrique de l’Est. Nous avons examiné les Monogènes présents sur les branchies de 18 espèces de Cichlidés appartenant à la radiation adaptative « superflock » du lac Victoria et de deux espèces représentant deux lignées anciennes et non étroitement apparentées. Nous avons trouvé une espèce de Gyrodactylus (Gyrodactylidae, Monogenea), Gyrodactylus sturmbaueri Vanhove, Snoeks, Volckaert & Huyse, 2011 et sept espèces de Cichlidogyrus (Dactylogyridae, Monogenea). Quatre espèces nouvelles sont décrites dans le présent travail : Cichlidogyrus pseudodossoui n. sp., C. nyanza n. sp., C. furu n. sp., C. vetusmolendarius n. sp.. Une est signalée mais non décrite formellement (trop peux d’individus recueillis, morphologiquement proche de C. furu n. sp.). Deux autres sont redécrites : Cichlidogyrus bifurcatus Paperna, 1960 and C. longipenis Paperna & Thurston, 1969. Nos résultats confirment que la faune des Monogènes des Cichlidés du lac Victoria fait preuve d’une richesse spécifique et d’une spécificité moins importante que celle du lac Tanganyika. Chez C. furu n. sp. la paire de crochet V étant nettement plus longue que les autres, il faudra reconsidérer le système de classification actuel des types de hapteurs chez les Cichlidogyrus, qui considère que tous les crochets (III à VII) ont la même taille. Quelques caractéristiques morphologiques de C. bifurcatus, C. longipenis et C. nyanza n. sp. pourraient être la preuve d’une ascendance commune avec des congénères présents chez d’autres Haplochrominés. De même, certains caractères indiqueraient que des représentants des Cichlidogyrus ont colonisé les Haplochrominés du lac Victoria, ou leurs ancêtres, au moins à deux reprises, ce qui est cohérent avec une colonisation du lac par deux lignées de cichlidés distinctes (Haplochromini and Oreochromini).

scholarly journals Evolutionary Dynamics of Structural Variation at a Key Locus for Color Pattern Diversification in Cichlid Fishes

2019 ◽  
Vol 11 (12) ◽  
pp. 3452-3465 ◽  
Author(s):  
Claudius F Kratochwil ◽  
Yipeng Liang ◽  
Sabine Urban ◽  
Julián Torres-Dowdall ◽  
Axel Meyer
Keyword(s):  
Evolutionary Dynamics ◽  
Lake Victoria ◽  
Functional Divergence ◽  
Color Pattern ◽  
Color Variation ◽  
Comparative Genomic ◽  
Color Patterns ◽  
East African ◽  
Cichlid Fishes ◽  
Adaptive Radiations

Abstract Color patterns in African cichlid fishes vary spectacularly. Although phylogenetic analysis showed already 30 years ago that many color patterns evolved repeatedly in these adaptive radiations, only recently have we begun to understand the genomic basis of color variation. Horizontal stripe patterns evolved and were lost several times independently across the adaptive radiations of Lake Victoria, Malawi, and Tanganyika and regulatory evolution of agouti-related peptide 2 (agrp2/asip2b) has been linked to this phenotypically labile trait. Here, we asked whether the agrp2 locus exhibits particular characteristics that facilitate divergence in color patterns. Based on comparative genomic analyses, we discovered several recent duplications, insertions, and deletions. Interestingly, one of these events resulted in a tandem duplication of the last exon of agrp2. The duplication likely precedes the East African radiations that started 8–12 Ma, is not fixed within any of the radiations, and is found to vary even within some species. Moreover, we also observed variation in copy number (two to five copies) and secondary loss of the duplication, illustrating a surprising dynamic at this locus that possibly promoted functional divergence of agrp2. Our work suggests that such instances of exon duplications are a neglected mechanism potentially involved in the repeated evolution and diversification that deserves more attention.

scholarly journals The coincidence of ecological opportunity with hybridization explains rapid adaptive radiation in Lake Mweru cichlid fishes

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Joana I. Meier ◽  
Rike B. Stelkens ◽  
Domino A. Joyce ◽  
Salome Mwaiko ◽  
Numel Phiri ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Great Lakes ◽  
Adaptive Radiation ◽  
Ecological Opportunity ◽  
African Great Lakes ◽  
Cichlid Fishes ◽  
Haplochromine Cichlid ◽  
Genetic Potential ◽  
Adaptive Radiations

AbstractThe process of adaptive radiation was classically hypothesized to require isolation of a lineage from its source (no gene flow) and from related species (no competition). Alternatively, hybridization between species may generate genetic variation that facilitates adaptive radiation. Here we study haplochromine cichlid assemblages in two African Great Lakes to test these hypotheses. Greater biotic isolation (fewer lineages) predicts fewer constraints by competition and hence more ecological opportunity in Lake Bangweulu, whereas opportunity for hybridization predicts increased genetic potential in Lake Mweru. In Lake Bangweulu, we find no evidence for hybridization but also no adaptive radiation. We show that the Bangweulu lineages also colonized Lake Mweru, where they hybridized with Congolese lineages and then underwent multiple adaptive radiations that are strikingly complementary in ecology and morphology. Our data suggest that the presence of several related lineages does not necessarily prevent adaptive radiation, although it constrains the trajectories of morphological diversification. It might instead facilitate adaptive radiation when hybridization generates genetic variation, without which radiation may start much later, progress more slowly or never occur.

scholarly journals Identification of a novel sex determining chromosome in cichlid fishes that acts as XY or ZW in different lineages

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Anna F. Feller ◽  
Vera Ogi ◽  
Ole Seehausen ◽  
Joana I. Meier
Keyword(s):  
Sex Determination ◽  
Sex Chromosome ◽  
Lake Victoria ◽  
Interspecific Crosses ◽  
Turnover Rates ◽  
Cichlid Fishes ◽  
Haplochromine Cichlid ◽  
Adaptive Radiations ◽  
Heterogametic Sex

AbstractSex determination systems are highly conserved among most vertebrates with genetic sex determination, but can be variable and evolve rapidly in some. Here, we study sex determination in a clade with exceptionally high sex chromosome turnover rates. We identify the sex determining chromosomes in three interspecific crosses of haplochromine cichlid fishes from Lakes Victoria and Malawi. We find evidence for different sex determiners in each cross. In the Malawi cross and one Victoria cross the same chromosome is sex-linked but while females are the heterogametic sex in the Malawi species, males are the heterogametic sex in the Victoria species. This chromosome has not previously been reported to be sex determining in cichlids, increasing the number of different chromosomes shown to be sex determining in cichlids to 12. All Lake Victoria species of our crosses are less than 15,000 years divergent, and we identified different sex determiners among them. Our study provides further evidence for the diversity and evolutionary flexibility of sex determination in cichlids, factors which might contribute to their rapid adaptive radiations.

Cartographical Quandaries: the Limits of Knowledge Production in Burton's and Speke's Search for the Source of the Nile

2008 ◽  
Vol 35 ◽  
pp. 455-479 ◽  
Author(s):  
Adrian S. Wisnicki
Keyword(s):  
Knowledge Production ◽  
Lake Tanganyika ◽  
Lake Victoria ◽  
Julius Caesar ◽  
East African ◽  
Blue Nile ◽  
Historical Series ◽  
The World ◽  
Limits Of Knowledge ◽  
White Nile

When he sighted the southern end of Lake Victoria on 3 August 1858, John Hanning Speke (1859b:397) realized that he had discovered the “source” of the White Nile, the most important tributary of the Nile proper, and so had “almost, if not entirely, solved a problem which it has been the first geographical desideratum of many thousand years to ascertain, and the ambition of the first monarchs of the world to unravel.” That Speke was an unknown explorer and that he had made his discovery on a solo “flying trip” during the East African Expedition of 1856-59, which, under the command of the renowned explorer Richard Francis Burton, had already also discovered Lake Tanganyika, made Speke's accomplishment all the more remarkable.As contemporaries soon asserted, Speke's discovery culminated a historical series of excursions, real and imagined, into the interior of Africa and placed Speke at the pinnacle of a line of explorers and geographers that ran from Herodotus, Julius Caesar, and Ptolemy to, in more recent times, James Bruce (the Scotsman who “discovered” the source of the Blue Nile, the second most important tributary of the Nile, in 1770), the German missionaries Ludwig Krapf and Johannes Rebmann (who “discovered,” respectively, the snow-capped mountains of Kilimanjaro in 1848 and Kenya in 1849), and noted “armchair geographers” like W.D. Cooley, Charles Beke, and James M'Queen.

Two new cichild species Neolamprologus (Teleostei: Cichlidae) from Lake Tanganyika, East Africa

Zootaxa ◽  
2007 ◽  
Vol 1612 (1) ◽  
pp. 25-44 ◽  
Author(s):  
PIET VERBURG ◽  
ROGER BILLS
Keyword(s):  
Lake Tanganyika ◽  
East Coast ◽  
Lake Victoria ◽  
Niche Partitioning ◽  
Sedimentation Rates ◽  
Rocky Shores ◽  
Ecological Differentiation ◽  
Cichlid Species ◽  
Large Numbers ◽  
Rocky Habitat

Two new cichlid species, Neolamprologus walteri sp. nov. and N. chitamwebwai sp. nov., from the Bangwe peninsula (Tanzania), on the east coast of Lake Tanganyika, are described. Both species belong to the N. savoryi species complex, characterised by a lunate tail with long filaments. Neolamprologus chitamwebwai and N. walteri are highly stenotopic species, restricted to rocky habitat. They occur sympatrically with each other and with two other species of the complex but occupy different microhabitats. Neolamprologus walteri lives in large numbers in sheltered areas with rubble substrate whereas N. chitamwebwai occurs in much lower numbers on more exposed parts of the rocky shores, with large boulders, lower sedimentation rates, coarser sediment, and higher visibility. The two new species although closely related, show clear ecological differentiation. Evidence of ecological differentiation between closely related sympatric cichlids is rare in literature. Closely related sympatric cichlids in the large African lakes (with literature mainly referring to Lake Victoria and Lake Malawi) have been suggested to differ little in diet and habitat use, which has encouraged the idea that cichlid species can coexist without niche partitioning. Our paper provides a different perspective with cichlids from Lake Tanganyika.

scholarly journals A revision of the genus Astatoreochromis (Teleostei, Cichlidae), East–Africa

2013 ◽  
Author(s):  
Gaspard Bayankimbona ◽  
Emmanuel Vreven ◽  
Jos Snoeks
Keyword(s):  
Lake Tanganyika ◽  
Lake Victoria ◽  
Taxonomic Revision ◽  
Valid Species ◽  
Type Specimens ◽  
Morphometric Measurements ◽  
Lake Victoria Region ◽  
Clear Differentiation ◽  
Pharyngeal Jaw ◽  
Comparable Size

A taxonomic revision of the cichlid genus Astatoreochromis is presented. Eighteen meristic and 23 morphometric measurements were taken on 185 individuals, including type specimens. While fin counts separate populations from the Lake Victoria region (Astatoreochromis alluaudi) from those of the Rusizi and Malagarazi rivers in the Lake Tanganyika basin (A. vanderhorsti and A. straeleni respectively), clear differentiation was not detected between the latter two. Mann-Whitney U-tests on specimens of comparable size from the two Tanganyika populations revealed significant differences in specimens < 75 mm SL, mainly in pharyngeal jaw proportions, but also in some other measurements on the head and body. However, these differences were not detected in specimens > 75 mm SL and Astatoreochromis vanderhorsti is herein considered a junior synonym of A. straeleni. A redescription of the two valid species of Astatoreochromis, A. alluaudi and A.straeleni, is provided.

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