Craniometric Characteristics of the Introduced Muskrats (Ondatra zibethicus Linnaeus, 1766) in Khar-Us Lake National Park, Western Mongolia

• Main Authors: Mogoltsog Otgonbaatar, Setev Shar
• Format: Article
• Language: English
• Published: National University of Mongolia 2019-11-01
• Series: Mongolian Journal of Biological Sciences
• Subjects: muskrat; morphometric analysis; skull measurement; age classes
• Online Access: http://mjbs.num.edu.mn/uploads/files/MJBS%20Volume%2017%20Number%201%202019/PDF/mjbs-17-57-64-otgonbaatar-2019.pdf

Muskrat is an invasive species in Mongolia, which came to Mongolia through Russia. Later, it was introduced into Khas-Us Lake in western Mongolia, and subsequently, the distribution of muskrats has expanded throughout the wetlands of this lake. Based on the 694 skulls, we studied craniometric variations among different age classes and sexes of muskrats. The skull measurements showed no statistically significant difference between juvenile male and female muskrats. However, there were slight differences between upper molar row length measurements of males and females in subadult and adult muskrats, whereas interorbital width measurement was significantly greater for females than males. This study also demonstrates that interorbital width does not show any correlation with other skull measurements for all age classes. The similarity between male and female skull measurements decreases with increased muskrat age, and the variations of all cranial measurements were greatly variable in juveniles, while these are stable in subadult and adult muskrats. We revealed no significant difference between the cranial measurements of the Mongolian population and those of the other countries, which indicate no craniometric changes occurred in muskrats during its acclimatization in Mongolia.