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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Three sympatric karyomorphs in the fish Astyanax fasciatus (Teleostei, Characidae) do not seem to hybridize in natural populations

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Author(s):
Ferreira-Neto, Maressa [1] ; Artoni, Roberto Ferreira [2] ; Vicari, Marcelo Ricardo [2] ; Moreira-Filho, Orlando [3] ; Martinez Camacho, Juan Pedro [4] ; Bakkali, Mohammed [4] ; de Oliveira, Claudio [1] ; Foresti, Fausto [1]
Total Authors: 8
Affiliation:
[1] Univ Estadual Paulista, Dept Morfol, Inst Biociencias, Botucatu, SP - Brazil
[2] Univ Estadual Ponta Grossa, Dept Biol Estrutural Mol Genet, Ponta Grossa, Parana - Brazil
[3] Univ Fed Sao Carlos, Programa Posgrad Genet Evolucao, BR-13560 Sao Carlos, SP - Brazil
[4] Univ Granada, Dept Genet, E-18071 Granada - Spain
Total Affiliations: 4
Document type: Journal article
Source: COMPARATIVE CYTOGENETICS; v. 6, n. 1, p. 29-40, 2012.
Web of Science Citations: 14
Abstract

Ninety individuals of the characid fish Astyanax fasciatus (Cuvier, 1819) were collected at Agua da Madalena stream (Botucatu, Sao Paulo, Brazil) and analyzed for diploid chromosome number 2n and karyotype composition as well as for the chromosomal location of the 5S and 18S ribosomal DNA (rDNA). Whereas no chromosome differences were associated with sex, three different karyomorphs with diploid chromosome numbers 2n=46, 2n=48 and 2n=50 were found. No intermediate 2n numbers were discovered. The 2n=50 karyomorph showed some differences in 18S rDNA location compared to the two other karyomorphs. Finally, all specimens with the 2n=46 karyomorph showed the presence of a partly heterochromatic macro supernumerary chromosome, which was absent in all individuals with the two other karyomorphs. All these results suggest that indviduals of the three different karyomorphs are not likely to hybridize in the examined populations. Our findings strongly suggest the presence of three separate species (sensu biological species concept) easily diagnosed on the basis of differences in the diploid chromosome numbers and other chromosomal markers. (AU)