Molecular Phylogenetic Relationships Among Crested-tailed Mice (Genus <Emphasis Type="Italic">Habromys</Emphasis>)

We examined genealogical relationships among six of seven species of crested-tailed mice (Habromys chinanteco, H. delicatulus, H. ixtlani, H. lepturus, H. lophurus, and H. simulatus) using DNA sequence data from the cytochrome-b gene. Gene trees based on maximum likelihood, Bayesian inference and maximum parsimony were largely congruent in that H. lepturus and H. ixtlani were closely related and formed the sister group to H. lophurus. All analyses also arranged H. chinanteco and H. simulatus as sister taxa. These results are concordant with the phenetic groupings of Carleton et al. (2002) based on morphology. Our unweighted maximum parsimony trees did not resolve placement of H. delicatulus relative to other taxa. However, analyses using weighted maximum parsimony, maximum likelihood and Bayesian inference optimality criteria recovered a sister group relationship between H. delicatulus and the clade comprised of ((H. lepturus H. ixtlani)(H. lophurus)). This relationship differs from the overall phenetic similarity of H. delicatulus with H. simulatus and H. chinanteco, influenced by the small size of these three taxa, but is consistent with some derived features of the phallus (Carleton et al., 2002). Based on our sequence data, a specimen from Michoacán, México, recently assigned to Peromyscus sagax likely was inadvertently misidentified (Tiemann-Boege et al., 2000) and actually represents a new locality record for H. delicatulus. Finally, we comment on the conservation status of species of Habromys.