Mitochondrial diversity and morphological variation of Marmosa murina (Didelphidae) in French Guiana

Abstract

The murine mouse opossum Marmosa murina is a widely distributed species in tropical South America. In northeastern South America, authors propose the recognition of several subspecies, of which 2 might be found in French Guiana: a paler taxon (M. murina murina) inhabiting the narrow coastal strip and a darker one (M. m. muscula) occurring in the inner rainforests. We present here results of molecular analyses for 2 mitochondrial fragments (cytochrome-b gene and control region) and morphological examination of 3 external and 15 cranial measurements. These data support the presence of only 1 subspecies (M. m. murina) in French Guiana based on the absence of genetic structure and morphological divergence. Nevertheless, it appears that M. murina shows substantial morphometric variation across the Guianan shield with respect to the dental measurement M1-M4. This suggests that M. murina could be a differentiated taxon in the Guianas, likely comprising more than one biological entity.