Comparative Myology of the Forelimb in Capuchin and Night Monkeys

ABSTRACT

Background: The capuchin monkey (Sapajus apella) and the night monkey (Aotus azarae infulatus) are primates with broad distribution in South America. Sapajus apella is best-studied species in the genus Cebus, and is commonly found in captivity in parks, zoos, and sorting centers in Brazil. Species in the genus Aotus have a primitive appearance with large eye sockets, and their nocturnal habits are unique among the apes today. Because these two species belong to the same order, they have similar morphological characteristics. In this work, we conduct a comparative study of the forelimb musculature between these two species to produce data for use in veterinary procedures.Materials, Methods & Results: Three capuchin monkey and three night monkey specimens were used, two females and one male for each species. Specimens were acquired from the National Center for Primates under approval from the Animal Research (CEPAN/IEC/SVS/MS) No. 008/2010. Specimens were frozen and donated after death by natural causes to the LaPMA (Animal Morphology Research Laboratory) at the Federal Rural University of Amazonia (UFRA). After being thawed in running water, the animals were fixed by intramuscular injection with 10% formaldehyde in aqueous solution and dissected to display thoracic limb muscle groups. Dissections were performed using basic instrumentation by creating a medial incision from t