The karyology of the Common shrew, Sorex araneus Linné, 1758 (Insectivora, Soricidae) in southwestern Germany

Presented is the karyotype of Sorex araneus from 4 trapping sites in southwestern Germany. From this species nearly 20 chromosomal races have so far been described. In the study area autosomal numbers of 2n_a= 22–24 were recorded. The characteristical metacentrics jl, hi, gm, kr and the acrocentrics n, o, p, q were identified by G-banding. The element kr shows Robertsonian polymorphism. The metacentrics only allow a classification of the studied populations as chromosomal race “Vaud” from Switzerland. The postglacial recolonization and the possible presence of other chromosomal races in the central and northern parts of Germany are briefly discussed. Different selection pressures act on metacentrics and acrocentrics in central populations of a chromosomal race in contrast to those living in contact zones of different chromosomal races. It is suggested that the smaller autosomal arms are subject to weaker selection pressure to be fixed as metacentrics.