28 research outputs found

    Two new species of Odontostilbe historically hidden under O. microcephala (Characiformes: Cheirodontinae)

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    Specimens historically identified as Odontostilbe microcephala from the upper rio ParanĂĄ and Andean piedmont tributaries of the rĂ­o Paraguay are reviewed and split in three species. We found that the distribution of O. microcephala is restricted to the Andean slope of the rĂ­o Paraguay basin. The species is distinguished from congeners with subterminal mouth by the elongate body, usually 10-12 gill rakers on upper branch and smaller horizontal orbital diameter (24.6-32.8 % HL, mean 28.7%). Specimens from upper rio ParanĂĄ constitute two new species, diagnosed from other Cheirodontinae by the presence of mesopterygoid teeth, grouped on median portion and forming a continuous row. The new species are distinguished from each other by having premaxillary teeth with five cusps vs. nine cusps and by the number of lamellae in left and right sides of central median raphe of olfactory rosette with 20-21 vs. 11-12.EspĂ©cimes historicamente identificados com Odontostilbe microcephala do rio ParanĂĄ e tributĂĄrios do rĂ­o Paraguay, foram revisados e separados em trĂȘs espĂ©cies. A distribuição de O. microcephala Ă© restrita ao sopĂ© andino da bacia do rĂ­o Paraguay. A espĂ©cie Ă© distinta das congĂȘneres com boca subterminal pela forma alongada, geralmente 10-12 rastros branquiais no ramo superior e menor diĂąmetro horizontal da Ăłrbita (24,6-32,8 % CC, mĂ©dia 28,7%). EspĂ©cimes do alto rio ParanĂĄ constituem duas espĂ©cies novas diagnosticadas de outros Cheirodontinae pela presença de dentes no mesopterigoide, agrupados em sua porção mĂ©dia e formando uma fileira continua. As novas espĂ©cies distinguem-se por ter dentes premaxilares com cinco cĂșspides vs. nove cĂșspides e pelo nĂșmero de lamelas nos lados esquerdo e direito da rafe central da roseta olfativa com 20-21 vs. 11-12

    Molecular phylogeny of the subfamily Stevardiinae Gill, 1858 (Characiformes: Characidae): classification and the evolution of reproductive traits

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    Abstract Background The subfamily Stevardiinae is a diverse and widely distributed clade of freshwater fishes from South and Central America, commonly known as “tetras” (Characidae). The group was named “clade A” when first proposed as a monophyletic unit of Characidae and later designated as a subfamily. Stevardiinae includes 48 genera and around 310 valid species with many species presenting inseminating reproductive strategy. No global hypothesis of relationships is available for this group and currently many genera are listed as incertae sedis or are suspected to be non-monophyletic. Results We present a molecular phylogeny with the largest number of stevardiine species analyzed so far, including 355 samples representing 153 putative species distributed in 32 genera, to test the group’s monophyly and internal relationships. The phylogeny was inferred using DNA sequence data from seven gene fragments (mtDNA: 12S, 16S and COI; nuclear: RAG1, RAG2, MYH6 and PTR). The results support the Stevardiinae as a monophyletic group and a detailed hypothesis of the internal relationships for this subfamily. Conclusions A revised classification based on the molecular phylogeny is proposed that includes seven tribes and also defines monophyletic genera, including a resurrected genus Eretmobrycon, and new definitions for Diapoma, Hemibrycon, Bryconamericus sensu stricto, and Knodus sensu stricto, placing some small genera as junior synonyms. Inseminating species are distributed in several clades suggesting that reproductive strategy is evolutionarily labile in this group of fishes.http://deepblue.lib.umich.edu/bitstream/2027.42/134621/1/12862_2015_Article_403.pd

    The program for biodiversity research in Brazil: The role of regional networks for biodiversity knowledge, dissemination, and conservation

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    The Program for Biodiversity Research (PPBio) is an innovative program designed to integrate all biodiversity research stakeholders. Operating since 2004, it has installed long-term ecological research sites throughout Brazil and its logic has been applied in some other southern-hemisphere countries. The program supports all aspects of research necessary to understand biodiversity and the processes that affect it. There are presently 161 sampling sites (see some of them at Supplementary Appendix), most of which use a standardized methodology that allows comparisons across biomes and through time. To date, there are about 1200 publications associated with PPBio that cover topics ranging from natural history to genetics and species distributions. Most of the field data and metadata are available through PPBio web sites or DataONE. Metadata is available for researchers that intend to explore the different faces of Brazilian biodiversity spatio-temporal variation, as well as for managers intending to improve conservation strategies. The Program also fostered, directly and indirectly, local technical capacity building, and supported the training of hundreds of undergraduate and graduate students. The main challenge is maintaining the long-term funding necessary to understand biodiversity patterns and processes under pressure from global environmental changes

    A new species of Boehlkea (Characiformes: Characidae: Stevardiinae) from the rio JapurĂĄ, Amazon basin, Brazil

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    ABSTRACT A new species of Boehlkea is described from rio JapurĂĄ, Amazon basin. The new species differs from B. fredcochui by the presence of a vertically elongate humeral spot (vs. absence), complete lateral line (vs. incomplete), four rows of scales below lateral line (vs. three), and lower number of branched anal-fin rays (17-21 vs. 22-25), and from B. orcesi by the higher number of maxillary teeth (13-14 vs. 5-12), greater head length (27.9-29.9% vs. 24.3-27.5% of SL), and by the color pattern (basal half of dorsal-fin, distal portion of pelvic-fin, lower caudal-fin lobe and anal-fin with black chromatophores vs. absence of black chromatophores in the fins)
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