Type specimens, taxonomic history, and genetic analysis of the Japanese dancing mouse or waltzer, Mus wagneri variety rotans Droogleever Fortuyn, 1912 (Mammalia, Muridae)

In the present paper, the existence and location of the type series of the Japanese dancing mouse or waltzer, Mus wagneri variety rotans Droogleever Fortuyn, 1912, are established, and a lectotype is designated. Available type specimens are measured, and some morphological parameters, sex, and general condition of the specimens are recorded. A literature survey was conducted, and an attempt is made to clarify the position of M. wagneri variety rotans in the taxonomy of Mus. A genetic analysis suggests that the type series of the Japanese dancing mouse represent a crossbred, or derivation of a crossbred, between the original Japanese dancing mouse of Mus musculus molossinus Temminck 1844 origin and European fancy or laboratory mice of Mus musculus domesticus Schwarz & Schwarz, 1943 origin. Much of their genome was replaced and occupied by Mus musculus domesticus type genome, probably through extensive breeding with European mice.