The myoglobin of primates: the Night Monkey, Aotes trivirgatus (Cebidae, Platyrrhini, Anthropoidea).

The amino acid sequence of the myoglobin of the South American Night Monkey, Aotes trivirgatus, is identical to that of the marmoset (Callithrix jacchus [1]) except for residue 21 which is isoleucine in the marmoset, like in all other anthropoids, but valine in Aotes. Analysis of a possible pathway of the evolution of Aotes myoglobin using 18 known primate myoglobin sequences [2-5] supports the classification of the Night Monkey within Anthropoidea and Platyrrhini but it indicates that this species might be more closely related to the marmoset (family Callitrichidae) than to the family Cebidae as a member of which it is commonly classified.

The chromosome complement of an Aotus hybrid.

Two divergent haploid chromosome sets were encountered in the chromosome complement of laboratory-born Aotus. Comparison of G-banded chromosomes of this individual with seven other established G-banded Aotus karyotypes revealed that this monkey is a hybrid offspring of two allopatric chromosome races (Brazilian Aotus X Colombian Aotus).

Observations on the geographic variation and skeletal development of Aotus.

The geographic pattern of coat color and craniometric variation were examined in Aotus. The coat color and pattern permitted recognition of the geographic origin of night monkeys from many parts of Latin America. The geographic pattern of craniometric variation differed from the pattern of phenotypic variation and led the authors to doubt the validity and usefulness of the currently recognized subspecific classification. Tooth eruption and bone ossification were studied in a sample of Aotus skeletons. Tentative criteria were presented for judging the ages of night monkeys by visual examination of their teeth or by x-ray of their teeth or bones.