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Article Reference Aquatic long-distance dispersal and vicariance shape the evolution of an ostracod species complex (Crustacea) in four major Brazilian floodplains.
Cladogenesis is often driven by the interplay of dispersal and vicariance. The importance of long-distance dispersal in biogeography and speciation is increasingly recognised, but still ill-understood. Here, we study faunal interconnectivity between four large Brazilian floodplains, namely the Amazon, Araguaia, Pantanal (on Paraguay River) and Upper Paraná River floodplains, investigating a species complex of the non-marine ostracod genus Strandesia. We use DNA sequence data from the mitochondrial COI and the nuclear Elongation Factor 1 alpha genes to construct molecular phylogenies and minimum spanning networks, to identify genetic species, analyse biogeographic histories and provide preliminary age estimates of this species complex. The Strandesia species complex includes five morphological and eleven genetic species, which doubles the known diversity in this lineage. The evolutionary history of this species complex appears to comprise sequences of dispersal and vicariance events. Faunal and genetic patterns of connectivity between floodplains in some genetic species are mirrored in modern hydrological connections. This could explain why we find evidence for (aquatic) long-distance dispersal between floodplains, thousands of kilometres apart. Our phylogenetic reconstructions seem to mostly indicate recent dispersal and vicariance events, but the evolution of the present Strandesia species complex could span up to 25 Myr, which by far exceeds the age of the floodplains and the rivers in their current forms.
Located in Library / RBINS Staff Publications 2018
Article Reference Karyotype variability and inter-population genomic differences in freshwater ostracods (Crustacea) showing geographical parthenogenesis
Transitions from sexual to asexual reproduction are often associated with polyploidy and increased chromosomal plasticity in asexuals. We investigated chromosomes in the freshwater ostracod species Eucypris virens (Jurine, 1820), where sexual, asexual and mixed populations can be found. Our initial karyotyping of multiple populations from Europe and North Africa, both sexual and asexual, revealed a striking variability in chromosome numbers. This would suggest that chromosomal changes are likely to be accelerated in asexuals because the constraints of meiosis are removed. Hence, we employed comparative genomic hybridization (CGH) within and among sexual and asexual populations to get insights into E. virens genome arrangements. CGH disclosed substantial genomic imbalances among the populations analyzed, and three patterns of genome arrangement between these populations: 1. Only putative ribosomal DNA (rDNA)-bearing regions were conserved in the two populations compared indicating a high sequence divergence between these populations. This pattern is comparable with our findings at the interspecies level of comparison; 2. Chromosomal regions were shared by both populations to a varying extent with a distinct copy number variation in pericentromeric and presumable rDNA-bearing regions. This indicates a different rate of evolution in repetitive sequences; 3. A mosaic pattern of distribution of genomic material that can be explained as non-reciprocal genetic introgression and evidence of a hybrid origin of these individuals. We show an overall increased chromosomal dynamics in E. virens that is complementary with available phylogenetic and population genetic data reporting highly differentiated diploid sexual and asexual lineages with a wide variety of genetic backgrounds.
Located in Library / RBINS Staff Publications 2018
Article Reference On Argentodromas bellanella gen. nov., sp. nov. (Crustacea, Ostracoda) from a stream in northern Argentina (South America). 
Located in Library / RBINS Staff Publications 2018
Article Reference Editorial. Happy birthday Hydrobiologia!  70 years young and still growing…
Located in Library / RBINS Staff Publications 2018
Article Reference Factors affecting the metacommunity structure of periphytic ostracods (Crustacea, Ostracoda): a deconstruction approach based on biological traits
Metacommunity studies using the deconstruction approach based on biological traits have received a great deal of attention in recent years as they often better describe characteristics of the species that reflect adaptations to a specific environment. This approach has not yet been used for ostracods, which are nevertheless highly diverse crustaceans and abundant in continental aquatic environments. Here, we investigate the influence of environmental and spatial factors on the metacommunity structure of periphytic ostracods in 27 tropical floodplain lakes in the Upper Paraná River floodplain (Brazil). An analysis of variance partitioning was used to estimate the relative importance of these factors (environmental and spatial) on both the entire community as well as after its deconstruction according to the biological traits (size and locomotion mode). Ostracods, regardless of body size, are good dispersers at regional scales. In addition, as expected, swimming ostracods were better dispersers at local scales than non-swimmers, which were influenced mainly by the diversity of aquatic macrophytes. Environmental factors (species sorting mechanism) seem important in structuring the entire ostracods metacommunity, as well as for most categories of biological traits. The unexplained variability remained high showing that other variables, not measured here, must be important. The analysis based on deconstruction, when compared to the analysis based on the metacommunity as a whole, contributed to a better assessment of ostracod metacommunity structuring.
Located in Library / RBINS Staff Publications 2018
Article Reference The proposed dropping of the genus Crassostrea for all Pacific cupped oysters and its replacement by a new genus Magallana: a dissenting view
Located in Library / RBINS Staff Publications 2017
Article Reference Getting to the roots of scales, feathers and hair: as deep as odontodes?
Located in Library / RBINS Staff Publications 2017
Article Reference Individual variation in the postcranial skeleton of the Early Cretaceous Iguanodon bernissartensis (Dinosauria: Ornithopoda)
Located in Library / RBINS Staff Publications 2017
Article Reference A new Jurassic theropod from China documents a transitional step in the macrostructure of feathers
Located in Library / RBINS Staff Publications 2017
Article Reference Distribution and paleoenvironmental framework of middle Miocene marine vertebrates along the western side of the lower Ica Valley (East Pisco Basin, Peru)
Located in Library / RBINS Staff Publications 2020