Identification of Sri Lankan Muroid Rodents using Hair Anatomy

We report here characteristic features of hair anatomy of all fifteen muroid rodent species occurring in Sri Lanka. We examined cuticular scale patterns, cross-sections, medullae patterns, hair profile and made measurements (length and maximum width) of dorsal guard hairs. We also developed a dichotomous key for identification of rodent species based on hair anatomy, supported with photomicrographs of cuticular scales, medullae and illustrations of cross-sections. All species except spiny rats ( Mus mayori and M. fernandoni ) can reliably be distinguished from each other using hair anatomy, in most cases using a combination of characters. Spiny rats can only be distinguished as a group. Cuticular scale patterns and cross-sections show more heterogeneity among species, compared to other characters. Medullary cell shape, their arrangement, maximum number of cells in the widest region of the hair, hair dimensions and profiles are also useful in species identification. Ceylon Journal of Science (Bio. Sci.) 43 (2): 17-30, 2014