We studied the karyotypes of two doradids, the rare and endangered Wertheimeria maculata and a derived Amazonian species, Hassar wilderi. Cytogenetic characterization was assessed using conventional staining (Giemsa), C-banding, and NOR banding. Both species had 2n = 58 chromosomes but differed in their chromosome formulae, 24 m + 14sm + 8st + 12a for W. maculata and 32 m + 16sm + 10st for H. wilderi. In W. maculata heterochromatin was mainly telomeric, and three chromosomes had a fully heterochromatic arm; in H. wilderi heterochromatin was also predominantly telomeric and evident in many more chromosomes. Hassar wilderi also presented one pair of homologues with a fully heterochromatic arm. In both species, nucleolar organizer regions were restricted to one pair of subtelocentric chromosomes. Assuming a basal position for W. maculata, we hypothesized that underlying conserved diploid and NOR-bearing chromosome numbers, chromosomal evolution in doradids has involved pericentric inversions and an increase of heterochromatic blocks. © 2006 Springer Science+Business Media B.V.
CITATION STYLE
Eler, E. S., Dergam, J. A., Vênere, P. C., Paiva, L. C., Miranda, G. A., & Oliveira, A. A. (2007). The karyotypes of the thorny catfishes Wertheimeria maculata Steindachner, 1877 and Hassar wilderi Kindle, 1895 (Siluriformes: Doradidae) and their relevance in doradids chromosomal evolution. Genetica, 130(1), 99–103. https://doi.org/10.1007/s10709-006-0023-4
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