Banding patterns of the chromosomes of two new karyotypes of the owl monkey, Aotus, captured in Panama.

Two new chromosome complements of Aotus trivirgatus griseimembra are described making a total of five different karyotypes observed in this subspecies inhabiting Panama and the northwestern part of Colombia, South America. Detailed comparisons of the G-banded chromosomes of these five karyotypes suggest that the polymorphism of chromosome numbers 56 and 55 in Panamanian Aotus and 54, 53, and 52 in Colombian Aotus stems primarily from a Robertsonian translocation mechanism involving pairs B13 and B14 (or A1). A second Robertsonian translocation mechanism involving pairs B28 and B29 (or A2) constitutes the karyotypic differences between the two chromosomal races.