Diversificação do complexo Oecomys bicolor (Rodentia: Cricetidae: Sigmodontinae)

• Ano de defesa: 2017
• Autor(a) principal: Paes, Rafaela Duda
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Doutorado em Biologia Animal; UFES; Programa de Pós-Graduação em Ciências Biológicas
• Palavras-chave em Português: Biogeography; Crypticism; Geographical distribution; Phylogeny; Genetics; Morphology; Criptismo; Biogeografia; Mimetismo (Biologia); Roedor x Distribuição geográfica; Filogenia; Genética animal; Roedor x Morfologia; Zoologia; 57
• Link de acesso: http://repositorio.ufes.br/handle/10/9922

Oecomys bicolor is a small orizomino rodent, with a wide geographic distribution from southeastern Central America to Brazil. Its taxonomy is still not well established, since morphological data assign ten synonyms to the species, which contrasts with genetic information, which shows the existence of more clades and indicates that the taxon is a species complex. Studies based on cytochrome b sequences indicate clusters with low mean intraclade divergences (< 2%), but with higher interclade divergences. In addition, only one study associated genetics with morphological data, which are shown to be polymorphic. Considering that mitochondrial genes accumulate homoplasies quickly and, therefore, lose resolution as the depth of tree branches increases, the construction of multigenic phylogenies with nuclear loci has been shown to be an efficient alternative, since they present evolutionary rates. slower, being useful for recovering deeper relationships. Thus, in order to elucidate the taxonomy of the group, the present work aimed to present a phylogenetic hypothesis for the O. bicolor complex, based on the analysis of qualitative and quantitative morphological data from specimens of all ages, covering the geographic distribution across the Americas, in addition to phylogenetic analyzes with partial sequences of a mitochondrial and two nuclear markers. The results recovered O. bicolor as a paraphyletic, with 11 geographically structured clades, which are accompanied by diagnosable morphotypes. Among these, two lineages are recognized as O. bicolor sensu stricto (widely present in the Amazon and trans-Andean forests) and O. cleberi (endemic to the Cerrado, Pantanal and Amazon of Brazil, exclusive to the distribution of O. bicolor), one is revalidated as O. nitedulus (restricted to the Guianas) and eight are potential new species, of which five are described (distributed in the Amazon, with cases of sympatry and limited by the Tapajós River). The propositions made about the revalidation of O. nitedulus and the recognition of eight new lineages increase the number of Oecomys species from 17 to 26. In addition, three other nominal taxa represent potential species complexes, evidencing the difficulty in identifying the species. species of the genus and the need for further taxonomic revisions.