Cytogenetic analyses of two endemic fish species from the São Francisco River basin: Conorhynchus conirostris and Lophiosilurus alexandri (Siluriformes)

Two Siluriformes species endemic to the São Francisco River basin were characterized by conventional and differential cytogenetic analyses involving C-banding, Ag-nucleolar organizer region (NOR) and chromomycin A3 (CMA3) staining, and FISH (fluorescent in situ hybridization) with 18S and 5S rDNA probes. Conorhynchus conirostris presents a higher diploid number (2n = 60) than those detected in Pimelodidae representatives, whereas Lophiosilurus alexandri, with a karyotype of 2n = 54 chromosomes, presents a chromosomal constitution similar to that found in the family Pseudopimelodidae. Plesiomo...

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