Variability of palatal ridges of the sable (Martes zibellina) in the Middle Amur region

It has been investigated intermolar palatal ridges in 148 individuals of sable from five areas of the Middle Amur. The authors have revealed variability in the number, morphology and asymmetry of the palatal ridges location. The total number of sable intermolar palatal ridges varies from 6 to 9. The variability in morphology reveals itself in the reduction of size, crushing; the formation of patchy margins, tuberculation, and fusion in the central part of the palate or near molars. Though the dominant phenotypes are symmetrical, the authors have revealed asymmetrical phenotypes in more than 25% of individuals. Rare phenotypes determine differences in geographical sable subpopulations in the considered area as soon as they mark any of the subpopulations with their presence. The authors have compared the age structure and representation of asymmetric phenotypes in the common pool and in separate geographical subpopulations.