Role of the squirrel monkey in parasitic disease research.

Much controversy exists regarding the species of the squirrel monkey. Napier and Napier (Whitney 1995) divide the squirrel monkeys into two species: Saimiri sciureus and Saimiri osterdii; the former is used in biomedical research. Hershkovitz prefers to use two groups of Saimiri based on facial characteristics and other factors, which include "Roman" and "Gothic" types. He suggests four species in all: boliviensis, sciureus, oerstedi, and ustus (Whitney 1995). Thorington classifies the Saimiri into two species, sciureus and madeirae, with four subspecies of 5. sciureus: sciureus, boliviensis, crassiquiarensis, and oerstedii (Thorington 1985). Squirrel monkeys have been karyotyped by their acrocentric chromosomes. Peruvian squirrel monkeys have 10 acrocentric chromosomes, Colombian types have 12, and Guyanan types have 14. The Costa Rican and Panamanian match the Peruvian karyotype of 10, and the Bolivian match the Colombian (Whitney 1995). This article is not intended to be a taxonomic review; however, it is important for readers to understand the complexity of the situation. Much of the research literature refers to the squirrel monkey only as S. sciureus. Other studies refer to them as Bolivian, Peruvian, or Guyanan phenotypes or refer to them by their karyotype. It is difficult or impossible at times to identify exactly what type of squirrel monkey was used in a study or whether the designations match the described karyotyopes of the animals. The squirrel monkey is critical to many studies involving human parasitic diseases. This article provides a review of the literature related to how this South American primate has been used in parasitic disease research.