Morphological analysis of two Asiatic water shrews (Eulipotyphla, Chimarrogale) from Vietnam

Abstract

The patterns of morphometric variation in external body and skull characters of two Asiatic water shrews (Chimarrogale himalayica and C. varennei) from Vietnam were analysed using different indices of variability. A total of 28 specimens were studied. Univariate, multivariate, and allometric analyses were conducted on 21 measurements of 26 skulls, while univariate analysis was conducted on three external measurements of 24 specimens. An external comparison showed that C. himalayica is larger than C. varennei. The mean (M) of skull measurements was used as an independent variable to regress the coefficient of variation (CV) and standard deviation (SD). The CVs did not differ significantly between two species and exhibited an inverse relationship with the M of skull measurements. CV trends of major functional parts of the skull showed that incisor length, brain-case size, postglenoid breadth, and mandible length presented opposing differences between the two species. In addition, C. himalayica had the highest allometric coefficient for the overall skull length, whereas C. varennei had the highest allometric coefficient for the postorbital region. Our study also revealed that the facial musculoskeletal system of C. himalayica is more developed than in C. varennei.