ISSN:
1573-6857
Keywords:
Astyanax scabripinnis
;
B chromosome
;
Characidae
;
cytogenetic
;
fish
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Specimens of Astyanax scabripinnisfrom three different altitudes (1920, 1800 and 700 m) along the Ribeirão Grande stream in the Campos do Jordão region (São Paulo State, Brazil) were investigated. The same diploid number, 2n = 50, was detected in the three populations, with the following karyotypic constitution: 6M, 22SM, 10ST and 12A. The populations located at 1920 and 1800 m altitude presented a high incidence of B chromosomes varying in number (0–2), shape (meta- and submetacentrics), size (large and small) and sex-related frequency (they were more frequent among females). The two morphologically variant B chromosomes probably evolved from a metacentric macrochromosome, which is the most commonly observed B chromosome in several A. scabripinnispopulations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004157901097
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