CYTOGENETICS OF THE GENUS ARVICANTHIS (RODENTIA, MURIDAE) .2. THE CHROMOSOMES OF 3 SPECIES FROM ETHIOPIA - ARVICANTHIS-ABYSSINICUS, ARVICANTHIS-DEMBEENSIS AND ARVICANTHIS-BLICKI

The karyotypes of three Ethiopian species of Arvicanthis, the lowland A. dembeensis, the highland A. abyssinicus, and the endemic mountain s pecies A. blicki are described. Their diploid numbers and autosomal Fu ndamental Numbers (aFN) are 2n=62 (aFN=62), 2n=62 (aFN=64), and 2n=48 (aFN=64), respectively. Except for a large submetacentric (no. 4) in A . abyssinicus and a small metacentric in A. dembeensis and A. abyssini cus, all their chromosomes are acrocentric, while the karyotype of A. blicki is characterized by having seven pairs of Rb metacentric chromo somes. C- and G-banding patterns and Ag-NORs positions were used to id entify chromosomal rearrangements (Rh translocations, pericentric inve rsions and heterochromatin additions). Phylogenetic hypotheses are sug gested based upon the comparisons among karyotypes investigated and wi th the previously described karyotype of 'A. niloticus' from West Afri ca (Benin).