Two new species of Characidium Reinhardt (Characiformes: Crenuchidae) from northeastern Brazilian coastal drainages
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چکیده
منابع مشابه
New species of Characidium (Characiformes: Crenuchidae) from the Rio Tapajós and Rio Xingu drainages, Pará, Brazil.
Characidium nana is described from the Rio Xingu and Rio Tapajós drainages. The new species is distinguished from all its congeners by the absence of the inner series of dentary teeth, the absence of the parietal branch of the supraorbital laterosensory canal, the incomplete lateral line, the lack of an adipose fin, the presence of a conspicuous dark blotch on caudal peduncle as well as an evid...
متن کاملOrigin of B chromosomes in Characidium alipioi (Characiformes, Crenuchidae) and its relationship with supernumerary chromosomes in other Characidium species
B chromosomes are apparently dispensable components found in the genomes of many species that are mainly composed of repetitive DNA sequences. Among the numerous questions concerning B chromosomes, the origin of these elements has been widely studied. To date, supernumerary chromosomes have been identified in approximately 60 species of fish, including species of the genus Characidium Reinhardt...
متن کاملCytogenetic divergence between two sympatric species of Characidium (Teleostei, Characiformes, Crenuchidae) from the Machado River, Minas Gerais, Brazil
Cytogenetic studies were performed on two sympatric species of Characidium, C. gomesi and C. cf. zebra, from the Grande River basin, Minas Gerais State, Brazil. Although both species had a chromosome number of 50 with a karyotype exclusively consisting of metaand submetacentric chromosomes, interspecific diversity was detected concerning the size of the two first chromosome pairs of the karyoty...
متن کاملMeiotic behavior and H3K4m distribution in B chromosomes of Characidium gomesi (Characiformes, Crenuchidae)
Characidium gomesi Travasso, 1956 specimens from the Pardo River have up to four heterochromatic supernumerary chromosomes, derived from the sex chromosomes. To access the meiotic behavior and distribution of an active chromatin marker, males and females of Characidium gomesi with two or three B chromosomes were analyzed. Mitotic chromosomes were characterized using C-banding and FISH with B ch...
متن کاملKaryotypic conservatism in samples of Characidium cf. zebra (Teleostei, Characiformes, Crenuchidae): Physical mapping of ribosomal genes and natural triploidy
Basic and molecular cytogenetic analyses were performed in specimens of Characidium cf. zebra from five collection sites located throughout the Tietê, Paranapanema and Paraguay river basins. The diploid number in specimens from all samples was 2n = 50 with a karyotype composed of 32 metacentric and 18 submetacentric chromosomes in both males and females. Constitutive heterochromatin was present...
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ژورنال
عنوان ژورنال: Neotropical Ichthyology
سال: 2015
ISSN: 1679-6225
DOI: 10.1590/1982-0224-20140106