Hair microstructure in peromyscine rodents revealed by multiscale microscopy

Abstract

The structural characteristics of dorsal guard hair were analyzed in twelve cricetid rodent species, including eleven peromyscine and one sigmodontine species, using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Hairs were collected from the dorsal region of adult specimens, prepared according to standard protocols, and examined to describe cuticular and medullary morphology. Optical microscopy revealed irregular mosaic-scale patterns with interspecific variation in density and contour. SEM confirmed diagnostic differences in scale size and arrangement, while TEM revealed variation in internal medullary organization. The combined use of these techniques provided morphological criteria useful for taxonomic assessment, particularly at higher taxonomic levels and established a comparative methodological framework for mammalogical studies. Our findings highlight the value of multitechnique hair analysis for taxonomic identification and for understanding structural adaptations in Neotropical rodents.