A revision of the akysid catfish genus Acrochordonichthys Bleeker

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75446/1/j.1095-8649.2001.tb02260.x.pd

A phylogenomic perspective on diversity, hybridization and evolutionary affinities in the stickleback genus Pungitius

Hybridization and convergent evolution are phenomena of broad interest in evolutionary biology, but their occurrence poses challenges for reconstructing evolutionary affinities among affected taxa. Sticklebacks in the genus Pungitius are a case in point: evolutionary relationships and taxonomic validity of different species and populations in this circumpolarly distributed species complex remain contentious due to convergent evolution of traits regarded as diagnostic in their taxonomy, and possibly also due to frequent hybridization among taxa. To clarify the evolutionary relationships among different Pungitius species and populations globally, as well as to study the prevalence and extent of introgression among recognized species, genomic data sets of both reference genome-anchored single nucleotide polymorphisms and de novo assembled RAD-tag loci were constructed with RAD-seq data. Both data sets yielded topologically identical and well-supported species trees. Incongruence between nuclear and mitochondrial DNA-based trees was found and suggested possibly frequent hybridization and mitogenome capture during the evolution of Pungitius sticklebacks. Further analyses revealed evidence for frequent nuclear genetic introgression among Pungitius species, although the estimated proportions of autosomal introgression were low. Apart from providing evidence for frequent hybridization, the results challenge earlier mitochondrial and morphology-based hypotheses regarding the number of species and their affinities in this genus: at least seven extant species can be recognized on the basis of genetic data. The results also shed new light on the biogeographical history of the Pungitius-complex, including suggestion of several trans-Arctic invasions of Europe from the Northern Pacific. The well-resolved phylogeny should facilitate the utility of this genus as a model system for future comparative evolutionary studies.Peer reviewe

A review of the catfish genus Pterocryptis (Siluridae) in Vietnam, with the description of two new species

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73958/1/j.1095-8649.2001.tb02367.x.pd

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation

We present a new map depicting the first global biogeographic regionalization of Earth's freshwater systems. This map of freshwater ecoregions is based on the distributions and compositions of freshwater fish species and incorporates major ecological and evolutionary patterns. Covering virtually all freshwater habitats on Earth, this ecoregion map, together with associated species data, is a useful tool for underpinning global and regional conservation planning efforts (particularly to identify outstanding and imperiled freshwater systems); for serving as a logical framework for large-scale conservation strategies; and for providing a global-scale knowledge base for increasing freshwater biogeographic literacy. Preliminary data for fish species compiled by ecoregion reveal some previously unrecognized areas of high biodiversity, highlighting the benefit of looking at the world's freshwaters through a new framework.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Postglacial recolonizations, watershed crossings and human translocations shape the distribution of chub lineages around the Swiss Alps

Background: Distributions of European fish species were shaped by glaciations and the geological history of river networks until human activities partially abrogated the restrictions of biogeographical regions. The nearby origins of the Rhine, Rhone, Danube and Po rivers in the Swiss Alps allow the examination of historical and human-influenced patterns in fish genetic structure over a small geographic scale. We investigated these patterns in the widespread European chub (Squalius cephalus) from the Rhone, Rhine and Danube catchments and its proposed southern sister species Italian chub (Squalius squalus) from the Po catchment. Results: A phylogenetic tree constructed from mitochondrial Cytochrome b and COI sequences was consistent with earlier work in that it showed a separation of European chub and Italian chub, which was also reflected in microsatellite allele frequencies, morphological traits and shape differences quantified by geometric morphometrics. A new finding was that the predominant mitochondrial haplotype of European chub from the Rhine and Rhone catchments was also discovered in some individuals from Swiss populations of the Italian chub, presumably as a result of human translocation. Consistent with postglacial recolonizations from multiple refugia along the major rivers, the nuclear genetic structure of the European chub largely reflected drainage structure, but it was modified by watershed crossings between Rhine and Rhone near Lake Geneva as well as between Danube and Rhine near Lake Constance. Conclusion: Our study adds new insights into the cyprinid colonization history of central Europe by showing that multiple processes shaped the distribution of different chub lineages around the Swiss Alps. Interestingly, we find evidence that cross-catchment migration has been mediated by unusual geological events such as drainage captures or watershed crossings facilitated by retreating glaciers, as well as evidence that human transport has interfered with the historical distribution of these fish (European chub haplotypes present in the Italian chub). The desirable preservation of evolutionarily distinct lineages will thus require the prevention of further translocations

Genetic and morphological analyses reveal a complex biogeographic pattern in the endemic barbel populations of the southern Italian peninsula

The Italian peninsula is a biodiversity hotspot, with its freshwater fish fauna characterized by high levels of local endemism. Two endemic fluvio-lacustrine fishes of the genus Barbus (barbel, family Cyprinidae) have allopatric distributions in the Tyrrhenian and Adriatic basins of Italy. Barbus plebejus inhabits the mid- to northern Adriatic basins, while B. tyberinus is widespread in all central-northern basins draining into the Tyrrhenian Sea. For basins in Southern Italy draining into the southern parts of these seas, there remains a knowledge gap on their barbel populations due to no previous genetic and morphological studies, despite their apparent biogeographic isolation. Correspondingly, this study quantified the presence and distribution of barbels in the Adriatic and Tyrrhenian basins of Southern Italy through genetic and morphological analyses of 197 fish sampled across eight populations. Testing of how local isolation has influenced the evolution and persistence of these populations was completed by examining sequence variation at two mitochondrial loci (cytochrome b and D-loop) and performing geometric morphometric analyses of body shape, plus measuring 11 morphometric and meristic characters. Phylogenetic and morphological analyses revealed the presence of two genetically distinct lineages that differed significantly from adjacent B. tyberinus and B. plebejus populations. These two new taxa, here described as SI1 and SI2 Barbus lineages, are highly structured and reflect a complex mosaic biogeographic pattern that is strongly associated with the underlying hydrographical scenarios of the basins. The geographic isolation of these basins thus has high evolutionary importance that has to be considered for maintaining endemism

A review of the systematic biology of fossil and living bony-tongue fishes, Osteoglossomorpha (Actinopterygii: Teleostei)

The bony-tongue fishes, Osteoglossomorpha, have been the focus of a great deal of morphological, systematic, and evolutionary study, due in part to their basal position among extant teleostean fishes. This group includes the mooneyes (Hiodontidae), knifefishes (Notopteridae), the abu (Gymnarchidae), elephantfishes (Mormyridae), arawanas and pirarucu (Osteoglossidae), and the African butterfly fish (Pantodontidae). This morphologically heterogeneous group also has a long and diverse fossil record, including taxa from all continents and both freshwater and marine deposits. The phylogenetic relationships among most extant osteoglossomorph families are widely agreed upon. However, there is still much to discover about the systematic biology of these fishes, particularly with regard to the phylogenetic affinities of several fossil taxa, within Mormyridae, and the position of Pantodon. In this paper we review the state of knowledge for osteoglossomorph fishes. We first provide an overview of the diversity of Osteoglossomorpha, and then discuss studies of the phylogeny of Osteoglossomorpha from both morphological and molecular perspectives, as well as biogeographic analyses of the group. Finally, we offer our perspectives on future needs for research on the systematic biology of Osteoglossomorpha

Metal Bioavailability in the Sava River Water

Metals present one of the major contamination problems for freshwater systems, such as the Sava River, due to their high toxicity, persistence, and tendency to accumulate in sediment and living organisms. The comprehensive assessment of the metal bioavailability in the Sava River encompassed the analyses of dissolved and DGT-labile metal species of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the river water, as well as the evaluation of the accumulation of five metals (Cd, Cu, Fe, Mn, and Zn) in three organs (liver, gills, and gastrointestinal tissue) of the bioindicator organism, fish species European chub (Squalius cephalus L.).This survey was conducted mainly during the year 2006, in two sampling campaigns, in April/May and September, as periods representative for chub spawning and post-spawning. Additionally, metal concentrations were determined in the intestinal parasites acanthocephalans, which are known for their high affinity for metal accumulation. Metallothionein concentrations were also determined in three chub organs, as a commonly applied biomarker of metal exposure. Based on the metal concentrations in the river water, the Sava River was defined as weakly contaminated and mainly comparable with unpolluted rivers, which enabled the analyses of physiological variability of metal and metallothionein concentrations in the chub organs, as well as the establishment of their constitutive levels