A preliminary survey of the fish fauna in the vicinity of Santa Ana del Yacuma in Bolivia (río Mamoré drainage)

The inventory of fish species of the río Mamoré sub-drainage in the Bolivian Amazon is far from being complete. This article informs about a small scale species inventory in the close vicinity of the town Santa Ana del Yacuma (drained by the río Yacuma, a left side tributary of the río Mamoré). Sampling four habitat types, 615 fish specimens belonging to 101 species were collected. Four species were reported for the first time from the río Mamoré sub-drainage: Aphyocharax rathbuni, Apistogramma erythrura, Apistogramma similis and Hyphessobrycon elachys. Differences in species composition among sampled habitats stress the importance of including a high number of collecting sites across biotic and abiotic environmental gradients to reliably survey species diversity.status: publishe

Update on the checklist of fish species of the Bolivian Amazon

In 2010 and 2011 new checklists of fish species occurring in the Bolivian Amazon have been published. We add 21 species to these lists of which two are new reports for Bolivia (Apistogramma urteagai Kullander, 1986 and Vandellia sanguinea Eigenmann, 1917). The other 19 taxa have been reported earlier for the Bolivian Amazon. Their absence on previous checklists indicate the difficulties to compile an overview of the current literature on the fish fauna of the Bolivian Amazon. The ichthyofauna of Bolivia is still not entirely known and many species await formal descriptions. Future collection efforts and taxonomic reviews might rise the number of known Bolivian fish species considerably in the near future.status: publishe

Differential modes of MHC class IIB gene evolution in cichlid fishes

Cichlid fishes are emblematic models for the study of adaptive radiation, driven by natural and sexual selection. Parasite mediated selection is an important component in these processes, and the evolution of their immune system therefore merits special attention. In this study, light is shed on the phylogeny of the b family of cichlid major histocompatibility complex (MHC) class IIB genes. Full-length coding sequences were used to reconstruct phylogenies using criteria of maximum parsimony, maximum likelihood and Bayesian inference. All analyses suggest monophyly of the b family of cichlid MHC class IIB genes, although sequences of the cichlid sister taxa are currently not available. Two evolutionary lineages of these genes, respectively encompassing the recently defined genomic regions DBB-DEB-DFB and DCB-DDB, show highly contrasting levels of differentiation. To explore putative causes for these differences, exon 2 sequences were screened for variation in recombination rate and strength of selection. The more diversified lineage of cichlid MHC class IIB b genes was found to have higher levels of both recombination and selection. This is consistent with the observation in other taxa that recombination facilitates the horizontal spread of positively selected sites across MHC loci and hence contributes to fast sequence evolution. In contrast, the lineage that showed low diversification might either be under stabilizing selection or is evolutionary constrained by its low recombination rate. We speculate whether this lineage might include MHC genes with non-classical functions.status: publishe

Parasite communities and population history predict immunogenetic diversity of natural populations of blunt-headed cichlids (Tropheus spp.) in Lake Tanganyika

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Dispersal pattern determines spatial structure of parasite communities and immunogenetic adaptation in two sympatric cichlid fish species from Lake Tanganiyka

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Host dispersal shapes host-parasite co-evolutionary dynamics in cichlid fishes

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Adaptive divergence among incipient species: a parasite perspective

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A link between host dispersal and parasite diversity in two sympatric cichlids of Lake Tanganyika

A major goal in ecology is to unravel how species assemblages emerge and how they are structured across the landscape. Host–parasite systems are particularly interesting in this context, as limited host dispersal may promote the differentiation of parasite communities. We examined whether the patterns of species diversity in Cichlidogyrus, a genus of monogenean parasitic flatworms with a direct life cycle, are consistent with the hypothesis that parasite diversity is driven by host dispersal. This was carried out by comparing two sympatric cichlid hosts (Tropheus moorii and Simochromis diagramma) with contrasting dispersal abilities. Genetic connectivity among host populations along the Zambian shoreline of Lake Tanganyika was estimated using microsatellite genotyping. Cichlidogyrus parasites were isolated and identified morphologically to the species level. Simochromis diagramma, a host with a high dispersal capacity, was infected by a low number of Cichlidogyrus species, and the parasite assemblages were similar among host populations. In contrast, T. moorii, a host with a low dispersal capacity, was infected by a large number of Cichlidogyrus species, and the parasite assemblages differed strongly among host populations. These outcomes were thus as expected from the hypothesis. Because of the strong host specificity of these Cichlidogyrus species, a lack of connectivity among host populations might facilitate allopatric speciation of the parasite.status: publishe

Contrasting parasite communities among allopatric colour morphs of the Lake Tanganyika cichlid Tropheus

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