Estudos cromossômicos e moleculares em Rhamdia (Pisces, Siluriformes, Heptapteridae): análise de relações evolutivas

Abstract

species complex. The division of Rhamdia species into a Cis-Andean group and a Trans-Andean group, as previously proposed, was also revalidated, although the genus seems not to be monophyletic. The cytogenetic data allowed establishing trends of chromosomal evolution within the group and a hypothesis for the origin and differentiation of supernumerary chromosomes could be drawn. The present work

Cryptic Diversity Between Two Imparfinis Species (Siluriformes, Heptapteridae) by Cytogenetic Analysis and DNA Barcoding

“…This great variation could possibly be related to the occurrence of non-Robertsonian chromosomal rearrangements, 4 where inversions are highlighted. 32 However, it cannot be discarded the fact that differences in the patterns of chromosomes measurements among researchers, the consideration of secondary constrictions as part or not of the chromosomes arms and the degree of condensation among the preparations could result in small differences in the karyotypic organization within the group.…”

“…[1][2][3][4] One of the main problems related to taxonomic and systematic conflicts involving Siluriformes, and specifically Heptapteridae, resides in the fact that many of these animals present cryptic diversity, which is reflected in the numerous propositions of species complexes for the group, mainly for the very specious genera or species with a wide geographic distribution. [5][6][7] Among the Heptapteridae genera, Imparfinis has been highlighted as taxonomically problematic, accounting for 21 recognized species, 9 of which occur in Brazil.…”

Estudos cromossômicos e moleculares em Loricariinae com ênfase em espécies de Rineloricaria (Siluriformes, Loricariidae): uma perspectiva evolutiva

“…Sequências de DNA mitocondrial têm sido utilizadas para inferir filogenias e padrões filogeográficos das mais diversas espécies de peixes (Bermingham e Martin, 1998;Inoue et al, 2001;Sivasundar et al, 2001;Perdices et al, 2002;Moyses, 2005;Kon et al, 2007;Kavalco, 2008;Garcia, 2009; entre outros). O presente trabalho apresenta, pela primeira vez, hipóteses sobre as relações filogenéticas de espécies de…”

“…drenagens independentes e corroborando a hipótese de ligação pretérita e de eventos de captura de cabeceiras estabelecido entre essas subbacias (Langeani, 1989;Weitzman e Malabarba, 1999;Ribeiro, 2006;Ribeiro et al, 2006;Serra et al, 2007). Garcia (2009), em sua tese de doutoramento, identificou uma estreita relação filogenética entre espécies de Rhamdia coletadas nas bacias do Paraíba do Sul e do Ribeira do Iguape, associando também os seus achados à história geológica comum entre estas duas bacias.…”