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Please use this identifier to cite or link to this item: http://acervodigital.unesp.br/handle/11449/111791
Title: 
Pseudoplatystoma metaense and P. orinocoense (Siluriformes: Pimelodidae) from the Orinoco basin, Venezuela: cytogenetic and molecular analyses
Author(s): 
Institution: 
  • Univ Oriente
  • Universidade Estadual Paulista (UNESP)
  • Univ Centroccidental Lisandro Alvarado
  • Univ Roma La Sapienza
ISSN: 
1125-0003
Sponsorship: 
  • Consejo de Investigacion, Universidad de Oriente, Venezuela
  • Sapienza University, Rome, Italy
Abstract: 
The genus Pseudoplatystoma includes catfish species distributed throughout the fresh waters of South America. These species are important fisheries resources and play a significant ecological role due to their piscivorous and migratory habits. The taxonomy of this genus is still debated: traditionally, only three species have been recognised, but recently, this number was raised to eight. The validity of these eight morphospecies, however, was not confirmed by two subsequent molecular phylogenetic studies, which identified either five or four main clades. In this study, we focused on the two morphospecies restricted to the Orinoco basin, P. metaense and P. orinocoense, which have been assigned to either the same or different clades in previous studies. We carried out cytogenetic analyses to describe their unknown karyotypes and to look for cytotaxonomic markers. We also analysed their mitochondrial sequences in order to assign the sampled specimens to the previously identified molecular clades. The two presumptive species show similar karyotypes (2n=56, 42 biarmed and 14 uniarmed chromosomes) and cytogenetic features in terms of the constitutive heterochromatin distribution and the number and location of minor and major ribosomal genes. Thus, no species-specific chromosome markers could be identified. The analysis of cytochrome b and cytochrome oxidase I mitochondrial genes (carried out by retrieving all the mtDNA Pseudoplatystoma sequences available in GenBank) distributed the sampled specimens into two distinct molecular clades and confirmed the need to re-evaluate, by parallel morphological and molecular analyses, the monophyly of some lineages.
Issue Date: 
1-Dec-2013
Citation: 
Italian Journal Of Zoology. Abingdon: Taylor & Francis Ltd, v. 80, n. 4, p. 526-535, 2013.
Time Duration: 
526-535
Publisher: 
Taylor & Francis Ltd
Keywords: 
  • COI
  • cyt b
  • FISH
  • karyotype
  • ribosomal genes
Source: 
http://dx.doi.org/10.1080/11250003.2013.840339
URI: 
Access Rights: 
Acesso restrito
Type: 
outro
Source:
http://repositorio.unesp.br/handle/11449/111791
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

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