Padrões de distribuição e diversidade genética das espécies Didelphis albiventris, Didelphis marsupialis e Didelphis aurita (Didelphimorphia: Didelphidae) de ocorrência no Nordeste brasileiro

Abstract

The species of the genus Didelphis are known popularly in Brazil as mucuras, timbus and sariguês (opossum or possum in English for all of them). Six are endemic to the Americas: five occur in South America and one in North America (D. virginiana). The species of this genus are classified into two groups: albiventris (opossum-the-earswhite) and marsupialis (opossums-of-ears-black), of which four occur in Brazil (D. albiventris, D. imperfecta, D. marsupialis and D. aurita). D. aurita is endemic to the Atlantic Forest, D. albiventris is typical of the Cerrado, D. marsupialis and D. imperfecta occur in Amazônia. Due to morphological similarities, D. aurita and D. marsupialis are identified only by molecular and morphometric data. In this study, it was aimed to understand the distribution patterns and genetic diversity of the species D. albiventris, D. marsupialis and D. aurita that occur in Brazilian Northeast, in order to infer as to its taxonomic and biogeographic problems. For that, it were analyzed samples (n=63) of the species D. albiventris (n=52), D. marsupialis (n=8) and D. aurita (n=4) from seven states in the Northeast of Brazil: Alagoas, Sergipe, Pernambuco, Paraíba, Ceará, Piauí and Maranhão, comprising the biomes Cerrado, Caatinga and Atlantic Forest. To get the molecular data, it was made DNA extraction from muscle tissue, liver, skin and tail and there was amplification and sequencing of rRNA 16S genes, Cytochrome b and Cytochrome Oxidase I. For the analysis of data, it were used specific software programs as well as bioinformatics platforms of free access. The data generated from the three molecular markers were efficient and showed the monophyly of D. albiventris in the Northeast region of Brazil, the identification of D. marsupialis for the Cerrado of Maranhão; thereby confirming its expansion to the east of Maranhão and distinct lineage of D. aurita for the Atlantic Forest in Alagoas. The populations’ study for D. albiventris in different states in the Northeast and different biomes did not evidence population structure indicating absence of biological barriers in the area of analyzed distribution. This study also allowed inferring as the sympatry of Didelphis groups for the species D. albiventris and D. marsupialis in the Cerrado of Maranhão, rare record for these species.