Identificação de marsupiais do Rio Grande do Sul através da microestrutura dos pelos-guarda

ABREU, M.S.L.; CHRISTOFF, A.U.; VIEIRA, E.M. 2011. Identificação de marsupiais do Rio Grande do Sul através da microestrutura dos pelos-guarda. Biota Neotropica 11(3):377-386.

Abstract: The analysis of mammalian hairs is a non-invasive technique that may help in the identification of Brazilian marsupials. Our objective was to identify microscopic patterns of marsupial guard-hairs (cuticle and medulla) from species with occurrence in the state of Rio Grande do Sul, southern Brazil. We also present a hair-based identification key for this group. Specifically for Monodelphis, a still taxonomically obscure genus that needs revision, we present detailed description of observed hair patterns. We obtained the analyzed material by collecting hair samples of marsupials captured in field or else deposited in different zoological collections. We identified hair patterns of ten marsupial species: Caluromys　lanatus, Chironectes　minimus, Didelphis　aurita, Didelphis　albiventris, Cryptonanus　guahybae, Gracilinanusagilis, Gracilinanusmicrotarsus, Lutreolinacrassicaudata, Micoureusparaguayanus and Philander　frenatus. Individuals of the Monodelphis genus were analyzed together, considered as part of the dimidiata group. We found three distinct patterns for this group, suggesting the possible occurrence of a third species besides the two already recognized (M. brevicaudis and M. 　dimidiata). These morphs show distinct distribution in the state, with some degree of distribution overlap. The analysis of microscopic patterns of mammal hairs allowed the successful identification of the great majority of marsupials that occur in the Rio Grande do Sul state. Our results suggest that the two Monodelphis species of the dimidiata group might occur with a distinct distribution in the state, one of them occupying mainly the northern part and the other one the eastern region, with some overlap in the central part of the state.