52 research outputs found

    A recent record of Romanogobio antipai (Actinopterygii, Cyprinidae, Gobioninae) from the Danube River in Bulgaria

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    The Danube delta gudgeon, Romanogobio antipai, has been considered to be extinct because there were no reliable recent observations. The latest record confirmed by a voucher specimen dating from 1992. We report here on a specimen of R. antipai collected in 2016 in the Bulgarian sector of the Danube main stream using a bottom drift net at a depth of 8 m. The species determination is supported by morphological examination including discriminant and cluster analyses in comparison with three syntypes and five non-type specimens of R. antipai, samples of the R. kesslerii species complex and R. vladykovi. Romanogobio antipai most clearly differs from both R. kesslerii and R. vladykovi by proportional measurements (caudal peduncle depth, head width, eye horizontal diameter, and interorbital width), from R. kesslerii also by the number of scales above and below the lateral line (6 and 4, respectively, (vs. commonly 5 and 3), and from R. vladykovi, also by 8½ branched dorsal-fin rays (vs. 7½) and the vertebral caudal region longer than the abdominal vertebral region (abdominal+caudal vertebrae 19+21 or 20+21, vs. commonly 20+20 or variants with a caudal region shorter than the abdominal one). The possibility that R. antipai represents a deep-water cophenotype of either R. kesslerii or R. vladykovi, cannot be excluded. The new record demonstrates that R. antipai is still extant in the lower Danube but may be restricted to greater depths in the main channel and the deltaic branches

    Novel Relationships among Lampreys (Petromyzontiformes) Revealed by a Taxonomically Comprehensive Molecular Data Set

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    The systematics of lampreys was investigated using complete mitochondrial cytochrome b sequences from all genera and nearly all recognized species. The families Geotriidae and Petromyzontidae are monophyletic, but the family Mordaciidae was resolved as two divergent lineages at the base of the tree. Within Petromyzontidae, the nonparasitic Lethenteron sp. S and Okkelbergia aepyptera were recognized as distinct lineages, Lethenteron morii and Lampetra zanandreai were moved to new genera, a sister species relationship was recovered between Caspiomyzon wagneri and Eudontomyzon hellenicus, and a clade was recovered inclusive of Entosphenus hubbsi and western North American Lampetra (L. ayresii and L. richardsoni). The placement of E. hellenicus as the sister species to C. wagneri reduces the number of genera comprised entirely of parasitic species to two, Geotria and Petromyzon. The recognition of distinct lineages for O. aepyptera and Lethenteron sp. S recognizes, for the first time, lineages comprised entirely of nonparasitic species. Apart from the results mentioned above, monophyly was supported for the multispecific genera Entosphenus, Eudontomyzon, Ichthyomyzon, Lampetra (restricted to European species), and Lethenteron. Intergeneric relationships within Petromyzontidae were poorly resolved, but separate clades inclusive of Entosphenus and Tetrapleurodon (subfamily Entospheninae) and one comprised of Eudontomyzon, Lampetra, and Okkelbergia were recovered

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

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    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

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    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

    Get PDF
    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

    Morphology-based taxonomic re-assessment of the Arctic lamprey, Lethenteron camtschaticum (Tilesius, 1811) and taxonomic position of other members of the genus

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    The lamprey genus Lethenteron Creaser & Hubbs, 1922 is widespread across Eurasia and North America, but the number and distribution of its constituent species is not firmly established. After a morphological examination of extant type material of the currently recognized species and their synonyms, Lethenteron mitsukurii (Hatta, 1901) is resurrected with Le. matsubarai Vladykov & Kott, 1978 as its junior synonym. Amongst nonparasitic species Le. reissneri (Dybowski, 1869) and Le. mitsukurii are confirmed as present in Japan and the former is also present on Sakhalin. An in-depth study of large samples of nonparasitic lamprey adults from Japan and Sakhalin Island is needed to determine whether the lower trunk myomere (< 66) individuals from these areas represent one or more undescribed species, or Le. mitsukurii, or Le. reissneri, or a mixture of these three alternatives. The material from the Anadyr Estuary identified by Berg (1931, 1948) as Lampetra japonica kessleri has been re-identified as Le. camtschaticum and there is no evidence that Le. kessleri occurs there. Lethenteron reissneri is reported from the Angara River system, Yenisei River drainage, Russia. Lethenteron alaskense Vladykov & Kott, 1978 is provisionally considered to be a junior synonym of Le. kessleri (Anikin, 1905). Petromyzon ernstii Dybowski, 1872, Ammocoetes aureus Bean, 1881, Petromyzon dentex Anikin, 1905, Lampetra mitsukurii major Hatta, 1911, and Lampetra japonica septentrionalis Berg, 1931 are junior synonyms of Petromyzon marinus camtschaticus Tilesius, 1811. A key is provided to adults of the six species recognized as belonging in the genus Lethenteron

    Morphology-based taxonomic re-assessment of the Arctic lamprey, Lethenteron camtschaticum (Tilesius, 1811) and taxonomic position of other members of the genus

    No full text
    The lamprey genus Lethenteron Creaser & Hubbs, 1922 is widespread across Eurasia and North America, but the number and distribution of its constituent species is not firmly established. After a morphological examination of extant type material of the currently recognized species and their synonyms, Lethenteron mitsukurii (Hatta, 1901) is resurrected with Le. matsubarai Vladykov & Kott, 1978 as its junior synonym. Amongst nonparasitic species Le. reissneri (Dybowski, 1869) and Le. mitsukurii are confirmed as present in Japan and the former is also present on Sakhalin. An in-depth study of large samples of nonparasitic lamprey adults from Japan and Sakhalin Island is needed to determine whether the lower trunk myomere (< 66) individuals from these areas represent one or more undescribed species, or Le. mitsukurii, or Le. reissneri, or a mixture of these three alternatives. The material from the Anadyr Estuary identified by Berg (1931, 1948) as Lampetra japonica kessleri has been re-identified as Le. camtschaticum and there is no evidence that Le. kessleri occurs there. Lethenteron reissneri is reported from the Angara River system, Yenisei River drainage, Russia. Lethenteron alaskense Vladykov & Kott, 1978 is provisionally considered to be a junior synonym of Le. kessleri (Anikin, 1905). Petromyzon ernstii Dybowski, 1872, Ammocoetes aureus Bean, 1881, Petromyzon dentex Anikin, 1905, Lampetra mitsukurii major Hatta, 1911, and Lampetra japonica septentrionalis Berg, 1931 are junior synonyms of Petromyzon marinus camtschaticus Tilesius, 1811. A key is provided to adults of the six species recognized as belonging in the genus Lethenteron

    Redescription of the Far Eastern brook lamprey Lethenteron reissneri (Dybowski, 1869) (Petromyzontidae)

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    Nonparasitic Lethenteron reissneri (Dybowski) is redescribed based on four syntypes (two adults and two ammocoetes) from the Onon and Ingoda rivers, Russia, and 15 topotypic specimens (seven metamorphosing ammocoetes and eight ammocoetes) from the Onon River system, Russia and Mongolia. Posterial teeth were not mentioned in the original description, but Berg (1931) stated that they were sometimes absent, which he later (Berg 1948) changed to usually absent, based on material (some of which we have re-identified as parasitic L. camtschaticum) from far outside of the type locality. The latter view has been widely accepted by subsequent authors. Unfortunately, the poor condition of the two adult syntypes did not permit verification of this character. However, a row of posterials was clearly visible in six of the seven topotypic metamorphosing ammocoetes and indicates their usual presence in the species. The first full description of the ammocoetes, including pigmentation, is provided. The present study restricts the distribution of L. reissneri to the Shilka and Songhua river systems within the Amur River basin, until a more geographically comprehensive study is undertaken. Additionally, in this study, feeding versus non-feeding at the adult stage, are considered to be valid taxonomic characters at the species level

    Contrasting morphology with molecular data: an approach to revision of species complexes based on the example of European Phoxinus (Cyprinidae)

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    Abstract Background Molecular taxonomy studies and barcoding projects can provide rapid means of detecting cryptic diversity. Nevertheless, the use of molecular data for species delimitation should be undertaken with caution. Especially the single-gene approaches are linked with certain pitfalls for taxonomical inference. In the present study, recent and historical species descriptions based upon morphology were used as primary species hypotheses, which were then evaluated with molecular data (including in type and historical museum material) to form secondary species hypotheses. As an example of cryptic diversity and taxonomic controversy, the European Phoxinus phoxinus species complex was used. Results The results of the revision showed that of the fourteen primary species hypotheses, three were rejected, namely P. ketmaieri, P. likai, and P. apollonicus. For three species (P. strandjae, P. strymonicus, P. morella), further investigation with increased data sampling was suggested, while two primary hypotheses, P. bigerri and P. colchicus, were supported as secondary species hypotheses. Finally, six of the primary species hypotheses (P. phoxinus, P. lumaireul, P. karsticus, P. septimanae, P. marsilii and P. csikii) were well supported by mitochondrial but only limitedly corroborated by nuclear data analysis. Conclusion The approach has proven useful for revision of species complexes, and the study can serve as an overview of the Phoxinus genus in Europe, as well as a solid basis for further work

    Corrigendum to «Contrasting morphology with molecular data: an approach to revision of species complexes based on the example of European (Cyprinidae)» by Palandačić et al. 2017

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    This corrigendum, in the sense of the Glossary of the International Code of Zoological Nomenclature (ICZN 1999, p. 102), is to ensure that the ICZN criteria for the availability of the two new nomenclatural acts, namely the designations of the neotype of Phoxinus csikii Hankó, 1922 and the lectotype of Phoxinus marsilii Heckel, 1836, are satisfied
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