Karyotypic variation in the long-whiskered catfish Pimelodus blochii Valenciennes, 1840 (Siluriformes, Pimelodidae) from the lower Tapajós, Amazonas and Trombetas Rivers
| Autor: | Ivanny Coelho da Fonseca, Frank Raynner V. Ribeiro, Luan Aércio Melo Maciel, Luís Reginaldo Ribeiro Rodrigues |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine Species complex Pimelodidae lcsh:QH426-470 010607 zoology Zoology rDNA Plant Science 01 natural sciences 03 medical and health sciences Genus Cellular & Organismal genetics Systematics Genetics Pimelodus Animalia Chordata species complex Vertebrata biology Actinopterygii Cenozoic Karyotype South America biology.organism_classification lcsh:Genetics 030104 developmental biology Taxon Osteichthyes catfish Pisces Animal Science and Zoology Amazon basin Americas Ploidy Siluriformes Research Article Biotechnology Catfish |
| Zdroj: | Comparative Cytogenetics, Vol 12, Iss 3, Pp 285-298 (2018) Comparative Cytogenetics 12(3): 285-298 Comparative Cytogenetics |
| ISSN: | 1993-0771 |
| Popis: | The genus Pimelodus LaCépède, 1803 comprises 35 formally recognized species distributed along the major neotropical river basins. Despite conservatism in diploid number with 2n=56, an intense variation of chromosomal morphology (karyotypic formula) has been documented in Pimelodus species. In the present study, we analyzed karyotypes of 20 specimens, identified as Pimelodusblochii Valenciennes, 1840 and collected from the lower courses of the Tapajós, Amazonas and Trombetas Rivers. The karyotypes were characterized by Giemsa conventional staining, C-banding, silver staining (Ag-NOR) and fluorescent in situ hybridization (FISH) with 5S and 18S rDNA probes. The karyotypes showed 2n=56 chromosomes in fish from the Tapajós River. In contrast, fish from the Amazonas and Trombetas Rivers had 2n=58. The nucleolus organizing regions were labeled on the short arm of an acrocentric chromosome as demonstrated by silver staining and FISH. Signals for 18S and 5S rDNA were co-localized on one chromosome pair. Our results demonstrate karyotypic divergence between Tapajós and Amazonas-Trombetas populations of P.blochii, interpreted as supporting the existence of a species complex in this taxon. |
| Databáze: | OpenAIRE |
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