An Aotus karyotype from extreme eastern Colombia

Abstract

The paper 'Aotus diversity and the species problem' (Defler and Bueno 2007, Primate Conserv. 22: 55-77) reviewed the distribution of the Aotus karyotypes in Panama and Colombia. It included a discussion of a night monkey from Maipures, Vichada, Colombia, that we captured live and karyotyped for a project at the Universidad de Los Andes, Bogotá, Colombia, in 1983. In 1984, in an unpublished manuscript, we hypothesized that this specimen was a natural hybrid of Aotus brumbacki. Our identification was based on the karyotype G-band patterns, capture location, fur color, and a skin and skull preserved at the Instituto de Desarrollo de Los Recursos Naturales y Renovables (INDERENA), Bogotá, now at the Instituto de Alejandro von Humboldt. Defler and Bueno (2007) had interpreted the karyotype by assuming that all 50 chromosomes were paired. However, the authors had used data from an indistinct photograph of a karyotype without G-bands. This prompted us to review our original data using contemporary digital techniques to re-examine the G-band pattern origins of the chromosomes and further define the karyotype. We used precise chromosome G-band measurements and digital arm-ratio analyses to provide convincing evidence that the specimen is in fact a hybrid of Aotus brumbacki.