Morphological Divergence in Endemic Gastropods from Lake Tanganyika: Implications for Models of Species Flock Formation

Palaios ◽  
1987 ◽  
Vol 2 (5) ◽  
pp. 413 ◽  
Author(s):  
Mark R. Johnston ◽  
Andrew S. Cohen
Keyword(s):  
Lake Tanganyika ◽  
Species Flock ◽  
Morphological Divergence

Ontogenetic mechanisms of explosive morphological divergence in the Lake Tana (Ethiopia) species flock of large African barbs (Labeobarbus; Cyprinidae; Teleostei)

2015 ◽  
Vol 46 (5) ◽  
pp. 294-306 ◽  
Author(s):  
F. N. Shkil ◽  
O. E. Lazebnyi ◽  
D. V. Kapitanova ◽  
Belay Abdissa ◽  
V. B. Borisov ◽  
...  
Keyword(s):  
Species Flock ◽  
Morphological Divergence ◽  
Lake Tana

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 On the origin of the Synodontis catfish species flock from Lake Tanganyika

2006 ◽  
Vol 2 (4) ◽  
pp. 548-552 ◽  
Author(s):  
Julia J Day ◽  
Mark Wilkinson
Keyword(s):  
Lake Tanganyika ◽  
Sequence Data ◽  
Phylogenetic Study ◽  
Species Flock ◽  
East African ◽  
Extrinsic Factors ◽  
Factors Affecting ◽  
Fossil Calibration ◽  
Mtdna Sequence ◽  
Species Flocks

Species flocks within Great Lakes provide unique insights into the factors affecting diversification. Lake Tanganyika (LT) is of particular interest because it contains many endemic groups for which general factors affecting diversification can be discerned. Here, we present the first phylogenetic study of the LT Synodontis (Siluriformes, Mochokidae) species flock using mtDNA sequence data. Our data reveal some previously unrecognized species diversity and indicate that the LT species flock is not monophyletic, and that two closely related clades of endemics may have independently colonized LT. Other comparable small species flocks are characterized by a single colonization event. Molecular date estimates of the timing of the initial within-lake diversification of the LT endemics, based on a fossil calibration, are comparable to those reported for other groups, suggesting that extrinsic factors maybe important common causes of clade diversification. The basal divergence in the sampled Synodontis reveals an East–West African faunal split seen in many terrestrial, but few aquatic groups, the timing of which coincides with East African rifting events.

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 Disentangling incomplete lineage sorting and introgression to refine species-tree estimates for Lake Tanganyika cichlid fishes

2016 ◽  
Author(s):  
Britta S Meyer ◽  
Michael Matschiner ◽  
Walter Salzburger
Keyword(s):  
Adaptive Radiation ◽  
Lake Tanganyika ◽  
Genetic Material ◽  
Species Tree ◽  
Ecological Niches ◽  
Species Flock ◽  
Cichlid Fishes ◽  
Coalescent Model ◽  
Multispecies Coalescent ◽  
History Of

Adaptive radiation is thought to be responsible for the evolution of a great portion of the past and present diversity of life. Instances of adaptive radiation, characterized by the rapid emergence of an array of species as a consequence to their adaptation to distinct ecological niches, are important study systems in evolutionary biology. However, because of the rapid lineage formation in these groups, and the occurrence of hybridization between the participating species, it is often difficult to reconstruct the phylogenetic history of species that underwent an adaptive radiation. In this study, we present a novel approach for species-tree estimation in rapidly diversifying lineages, where introgression is known to occur, and apply it to a multimarker dataset containing up to 16 specimens per species for a set of 45 species of East African cichlid fishes (522 individuals in total), with a main focus on the cichlid species flock of Lake Tanganyika. We first identified, using age distributions of most recent common ancestors in individual gene trees, those lineages in our dataset that show strong signatures of past introgression. This led us to formulate three hypotheses of introgression between different lineages of Tanganyika cichlids: the ancestor of Boulengerochromini (or of Boulengerochromini and Bathybatini) received genomic material from the derived H-lineage; the common ancestor of Cyprichromini and Perissodini experienced, in turn, introgression from Boulengerochromini and/or Bathybatini; and the Lake Tanganyika Haplochromini and closely related riverine lineages received genetic material from Cyphotilapiini. We then applied the multispecies coalescent model to estimate the species tree of Lake Tanganyika cichlids, but excluded the lineages involved in these introgression events, as the multispecies coalescent model does not incorporate introgression. This resulted in a robust species tree, in which the Lamprologini were placed as sister lineage to the H-lineage (including the Eretmodini), and we identify a series of rapid splitting events at the base of the H-lineage. Divergence ages estimated with the multispecies coalescent model were substantially younger than age estimates based on concatenation, and agree with the geological history of the Great Lakes of East Africa. Finally, we formally tested the three hypotheses of introgression using a likelihood framework, and find strong support for introgression between some of the cichlid tribes of Lake Tanganyika.

scholarly journals Trophic specialisation reflected by radular tooth material properties in an “ancient” Lake Tanganyikan gastropod species flock

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wencke Krings ◽  
Marco T. Neiber ◽  
Alexander Kovalev ◽  
Stanislav N. Gorb ◽  
Matthias Glaubrecht
Keyword(s):  
Mechanical Properties ◽  
Lake Tanganyika ◽  
Ecological Niches ◽  
Species Flock ◽  
Trophic Specialization ◽  
East African ◽  
Tooth Morphology ◽  
Lake Formation ◽  
Feeding Substrate ◽  
Radular Tooth

Abstract Background Lake Tanganyika belongs to the East African Great Lakes and is well known for harbouring a high proportion of endemic and morphologically distinct genera, in cichlids but also in paludomid gastropods. With about 50 species these snails form a flock of high interest because of its diversity, the question of its origin and the evolutionary processes that might have resulted in its elevated amount of taxa. While earlier debates centred on these paludomids to be a result of an intralacustrine adaptive radiation, there are strong indications for the existence of several lineages before the lake formation. To evaluate hypotheses on the evolution and radiation the detection of actual adaptations is however crucial. Since the Tanganyikan gastropods show distinct radular tooth morphologies hypotheses about potential trophic specializations are at hand. Results Here, based on a phylogenetic tree of the paludomid species from Lake Tanganyika and adjacent river systems, the mechanical properties of their teeth were evaluated by nanoindentation, a method measuring the hardness and elasticity of a structure, and related with the gastropods’ specific feeding substrate (soft, solid, mixed). Results identify mechanical adaptations in the tooth cusps to the substrate and, with reference to the tooth morphology, assign distinct functions (scratching or gathering) to tooth types. Analysing pure tooth morphology does not consistently reflect ecological specializations, but the mechanical properties allow the determination of eco-morphotypes. Conclusion In almost every lineage we discovered adaptations to different substrates, leading to the hypothesis that one main engine of the flock’s evolution is trophic specialization, establishing distinct ecological niches and allowing the coexistence of taxa.

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