Karyotypes of five tetragonopterinae species (pisces, characidae) from Argentina

Abstract

Karyotypic studies on five species (Characidae, Tetragonopterinae) from Argentina were carried out. Mitotic preparations from the kidney tissues were made by direct and short term culture methods. C-banding and silver staining was performed by conventional techniques. Astyanax bimaculatus, Gymnocorhimbus ternetzi and Moenkhausia sanctaefilomenae showed 2n=50 chromosomes, with different karyotypic formulaes. Tetragonopterus argenteus showed 52 chromosomes and Astyanax schubarti 2n=36 chromosomes. One pair of NORs was detected in most of species except in A. bimaculatus which showed numerical variation (1-6 carrier chromosomes) and size heteromorphism. The present paper reports the first cytogenetic study on the Tetragonopterinae from Argentina.